IN THE HIGH COURT OF JUSTICE Claim No. CO/1322/2019
QUEEN’S BENCH DIVISION
THE ADMINISTRATIVE COURT
B E T W E E N :
(On the application of THE ENGLISH DEMOCRATS)
- and –
THE PRIME MINISTER
- and –
THE SECRETARY OF STATE FOR EXITING THE EUROPEAN UNION
WRITTEN SUBMISSIONS OF THE CLAIMANT
1 The Claimant is a limited company (reg. no. 6132268) and a political party registered with the Electoral Commission pursuant to the Political Parties, Elections and Referendums Act 2000 (‘PPERA’).
2 The Prime Minister exercises powers, on behalf of the Crown and pursuant to statute, concerning relations between the United Kingdom and the European Union (‘the EU’; ‘the Union’). This claim concerns the derivation and extent of those powers.
3 The Secretary of State for Exiting the European Union (‘the Secretary of State’) has responsibility for legislation and policy relating to the UK’s departure from the EU.
4 The Claimant seeks a declaration that the purported extension of the United Kingdom’s membership of the EU, purportedly agreed in March 2019, was void; and that, as a matter of domestic, international and EU law, the United Kingdom withdrew from the European Union at 11 pm on 29.3.2019, since when the Treaty on European Union (‘the TEU’) and the Treaty for the Functioning of the European Union (‘the TFEU’, together ‘the Treaties’) have ceased to apply. The claim is made on the grounds that the Prime Minister had no statutory power to extend and could not do so exercising the Prerogative powers of the Crown.
5 The Claimant also applies to amend its claim to seek a further declaration that the European Union (Withdrawal) Act 2018 (Exit Day) (Amendment) Regulations 2019 (‘the Exit Day Regulations’) are void, having been made other than in the defined circumstances in which such regulations were permitted to amend the European Union Withdrawal Act 2018 (‘the 2018 Act’); and that the passing of ‘exit day’ has had the legislative consequences provided for by the 2018 Act.
6 The Court is asked to read the Statement of Facts and Grounds first.
7 These submissions (also served on the Defendants) are intended to assist the Court with its initial legal analysis of whether the claim is arguable. The Court’s indulgence is sought, for reasons explained in the accompanying correspondence, to take them into account alongside the Statement of Facts and Grounds before determining permission. This claim is of the highest constitutional importance and there have also been two significant developments (the passing of a Bill in the House of Commons affecting the ability of the Crown to request extensions and a further purported request by the Prime Minister), outlined below, since the claim was issued.
FACTUAL AND LEGISLATIVE BACKGROUND
8 On 23.6.2016, in a referendum held in accordance with the European Union Referendum Act 2015, the United Kingdom electorate voted to leave the European Union.
9 The right of a Member State to withdraw from the EU is regulated by Article 50 (‘A50’; ‘A50.1’, etc) of the TEU, which is as follows:
1. Any Member State may decide to withdraw from the Union in accordance with its own constitutional requirements.
2. A Member State which decides to withdraw shall notify the European Council of its intention. In the light of the guidelines provided by the European Council, the Union shall negotiate and conclude an agreement with that State, setting out the arrangements for its withdrawal, taking account of the framework for its future relationship with the Union. That agreement shall be negotiated in accordance with Article 218(3) of the Treaty on the Functioning of the European Union. It shall be concluded on behalf of the Union by the Council, acting by a qualified majority, after obtaining the consent of the European Parliament.
3. The Treaties shall cease to apply to the State in question from the date of entry into force of the withdrawal agreement or, failing that, two years after the notification referred to in paragraph 2, unless the European Council, in agreement with the Member State concerned, unanimously decides to extend this period.
4. For the purposes of paragraphs 2 and 3, the member of the European Council or of the Council representing the withdrawing Member State shall not participate in the discussions of the European Council or Council or in decisions concerning it.
A qualified majority shall be defined in accordance with Article 238(3)(b) of the Treaty on the Functioning of the European Union.
5. If a State which has withdrawn from the Union asks to rejoin, its request shall be subject to the procedure referred to in Article 49.
10 Subsequent to the referendum, the Divisional Court and (on appeal) the Supreme Court found that the Prerogative power of the conduct of foreign relations could not be exercised to notify the EU of the UK’s withdrawal as (inter alia) it would remove rights emanating from EU law through the conduit of the European Communities Act 1972 (‘the 1972 Act’) and it would frustrate the statutory powers and purpose of the said Act (Miller v Secretary of State for Exiting the European Union  UKSC 5).
11 Consequently, Parliament (in the European Union (Notification of Withdrawal) Act 2017 (‘the 2017 Act’)) granted the Prime Minister a statutory power to notify the European Council (‘the Council’) of the UK’s intention to withdraw from the Union under A50. This power was exercised by the Prime Minister on 29.3.2017 (‘the Notification’). Accordingly, the UK would leave the European Union after a period (‘the A50 period’) of two years after the Notification (which would thereby end on 29.3.2019) unless either: (a) an agreement was concluded with the Union for the UK’s withdrawal earlier than that date; or (b) the Council unanimously decided to extend the A50 period ‘in agreement with the Member State concerned’ (A50.3). It is the Claimant’s case that a Member State may agree to extend the period only in accordance with its own constitutional arrangements: words expressly restricting the exercise of a Member State’s power to notify (by A50.1) and found by the Court of Justice of the European Union (‘the CJEU’) to restrict a Member State’s power to revoke its notification (Wightman & Others v Secretary of State ((2018) C-621/18).
12 Parliament enacted the European Union Withdrawal Act in 2018 (‘the 2018 Act’), which provided that ‘exit day’, on which day the Treaties were to ‘cease to apply’ to the UK, was 29.3.2019. The 2018 Act provides for the continuing domestic effect of EU law as it was on ‘exit day’ and the repeal of the 1972 Act on exit day; and allows the definition of ‘exit day’ to be amended by statutory instrument. The power to amend that definition may be exercised only where the Treaties are to cease to apply is different to 29.3.2019 (s 20 (4) (a)). The Act does not purport to provide HM Government with any statutory powers in relation to the conduct of relations with the EU on the international plane (as is submitted below). Much of the 2018 Act (including s 1, under which the 1972 Act would be repealed on exit day) is not in force.
13 During the A50 period, the EU and the UK government negotiated a draft Withdrawal Agreement (‘the Draft WA’) that, were it ratified by the UK and agreed by a qualified majority of the Council with the consent of the European Parliament (‘the EP’), would have been a concluded agreement by which the UK would have withdrawn from the Union. However, s 13 (1) (b) of the 2018 Act prevents UK ratification of a negotiated withdrawal agreement unless and until it is ‘approved by a resolution of the House of Commons on a motion moved by a Minister of the Crown’. No such resolution having been approved, the Council having failed to conclude ratification by a qualifying majority vote and the EP having not consented, no withdrawal agreement has been concluded between the UK and the EU.
14 On 20.3.2019 the Prime Minister asked the Council, purportedly on behalf of the UK, to extend the A50 period to 30.6.2019. At a meeting held on 21.3.2019, the Council decided unanimously to offer to extend the A50 period to one of two dates: (a) 22.5.2019 if the UK Parliament had, by resolution on or before 12.4.2019, approved the draft WA; or (b) otherwise on 12.4.2019.
15 On 22.3.2019, through a letter from Sir Tim Barrow, the UK’s permanent representative to the EU, the Prime Minister agreed to the extension of the A50 period on the terms set by the Council, doing so purportedly on behalf of the United Kingdom.
16 On 28.3.2019, purportedly pursuant to the power granted by s 20 (4) (a) of the 2018 Act, the Exit Day Regulations purported to come into effect by affirmative resolutions of both Houses of Parliament. The said Regulations purport to change ‘exit date’ to the dates by which the Council offered to extend the A50 period, as set out in para 12 above.
17 Since 29.3.2019 (and since this claim was issued) there have been two further developments of significance.
18 First, on 3.4.2019, after the House of Commons voted to disapply its long-standing procedural rule that the business of HM Government should have priority at all its sittings, voted for the First to Third Readings of a backbench Bill introduced by the Rt Hon Yvette Cooper MP that would make the UK’s request for and agreement to an extension of the A50 period subject to statutory control. The Bill was debated in the House of Lords on 4.4.2019 but has yet to complete its three readings in that House. It is of note that the Speaker of the House of Commons ruled that HM’s Consent was not required before the Bill was introduced. This strongly suggests that the Speaker was advised that the Bill would not affect the Prerogative and acted on that advice; and that there is therefore no Prerogative power to extend.
19 Secondly, on 5.4.2019 the Prime Minister wrote again to the President of the Council, purporting to request on behalf of the UK a further extension of the A50 period (on the understanding that the period had already been extended and the UK remained a member of the EU). This request will be considered at a meeting of the Council on 11.4.2019, the day before the expiry of the purported extension to the A50 period. It is evidence in practice of the lack of restriction by A50 on the ability of a Member State to request, the Council to offer and a Member State to agree to further extensions of the period.
20 The Claimant’s case is that the Prime Minister had no lawful authority to ask the Council to extend the period before the UK leaves the EU, or to agree to any extension proposed by the Council in response; and that her purported acceptance of the Council’s offer to extend the A50 period was, accordingly, void. It is thereby averred that, as a matter of domestic, international and EU law, the United Kingdom withdrew from the European Union at 11 pm on 29.3.2019, since when the Treaties have ceased to apply.
21 Moreover, it is averred that the Exit Day Regulations are void as the condition precedent that must be satisfied before they may come into effect, that the date on which the Treaties were to cease to apply to the UK was different to 29.3.2019, was not met. Consequently, the parts of the 2018 Act due to come into force on exit day have been in force since 29.3.2019.
THE EFFECT OF AN EXTENSION ON DOMESTIC LAW
22 The consequence of notification under A50 was recognised by the Supreme Court to have the inevitable consequence that, but for an extension, the Treaties would cease to apply to the United Kingdom after two years (Miller, paras 36 and 94, in which Lord Pannick QC’s analogy of a bullet being fired at notification, to reach inevitably the ‘target’ of withdrawal, was adopted). This position must now be modified by the decision of the CJEU that unilateral revocation of notification is possible (Wightman, albeit the Supreme Court accepted that there was no more an agreed position to accept and not argue the irrevocability of notification).
23 Parliament, in passing the 2017 Act, provided the Prime Minister with the power to notify, thereby ‘firing the bullet’ that would lead to the UK’s withdrawal from the EU. It was only through that statutory power that EU law could be ended but by the exercise of that power EU law would automatically cease to apply (through the conduit of the 1972 Act) after two years. The only exception was through extension of the A50 period or revocation of notification, neither of which are contemplated by the 2017 Act.
24 Were the A50 period extended (as HM Government claim that it has been), continued EU membership will have considerable consequences on domestic law. In particular and inter alia:
(1) All EU Regulations would have continued direct effect;
(2) The UK would be under a continuing obligation to incorporate Directives into domestic law; and those Directives may be relied on directly if any secondary legislation departs from the Directives by more than the margin of appreciation;
(3) UK courts must continue to comply with EU law, including both legislation and the case law of the CJEU;
(4) UK courts continue to have the power to refer questions of EU law to the CJEU, after which its decisions will be binding;
(5) The developments of EU law to which the UK would be subject in the period of the extension could include criminal offences the UK would be required to create;
(6) The UK would be obliged to pay into the EU budget; and, such budgetary contributions being calculated on a daily basis, payments have been made (whether lawfully or otherwise) from 11 pm on 29.3.2019; and
(7) The EU Arrest Warrant would continue to apply, affecting the rights (including under Articles 5 and 6 of the European Convention on Human Rights and Fundamental Freedoms (‘the Convention’)) of all residents of the UK.
25 The above effects of EU membership on EU law were described, in Miller, as ‘a new constitutional process for making law in the United Kingdom’ (para 62), created by the ‘constitutional character’ of the 1972 Act (para 67). EU law is not comparable to delegated legislation: for as long as the conduit of the 1972 Act continues to exist ‘EU legislative institutions… make laws independently of Parliament’ (para 68).
26 There is no limitation to the length of the period by which A50 may be extended. It is not merely reductio ad absurdum to posit that, were the Crown able to ask for and agree to extensions of the period through its Prerogative, such extensions could change the law of the United Kingdom for years afterwards: either through one or a series of extensions. The recent history of the applications that have been (purportedly) made and granted demonstrate the far-reaching nature of the power presumed by the Crown.
27 First, the Prime Minister’s initial request for an extension was agreed by the EU only on particular terms that the Draft WA must be approved by the House of Commons) and with a varied length dependent upon the actions of the House. There was no attempt to agree these variations to the original request before the Prime Minister agreed to them – the making of the Exit Day Regulations post-dated that acceptance, by which date (were the Prime Minister’s actions lawful) the period had already been extended in EU and domestic law.
28 Secondly, the Prime Minister has since requested a second extension with no prior Parliamentary resolution and would (were her interpretation of her powers correct) have the power to agree to an extension for as long as the EU were prepared to offer without any further Parliamentary involvement whatsoever.
29 The purported agreement to the extension and the Exit Day Regulations did not repeal the 1972 Act. Section 1 of the 2018 Act was not then and is not now in force. Consequently, were Exit Day to have passed (as the Claimant’s maintain that it has) its effect on domestic law would in theory have been limited to the consequential and transitional provision set out in s 23 (8) of the Act (relating to the repeal of the European Union Act 2011); and Schedule 9 (additional repeals of the same Act).
30 Yet, while the 1972 Act would not technically have been repealed, it would have no continuing effect on domestic law if the UK withdrew from the EU in those circumstances: it would become (and the Claimant’s case is that it has become) a hollow shell. Section 2 (1) of the 1972 Act, headed “General Implementation of Treaties”, was in these terms:
“All such rights, powers, liabilities, obligations and restrictions from time to time created or arising by or under the Treaties, and all such remedies and procedures from time to time provided for by or under the Treaties, as in accordance with the Treaties are without further enactment to be given legal effect or used in the United Kingdom shall be recognised and available in law, and be enforced, allowed and followed accordingly …”
31 The Supreme Court adopted Professor Finnis’s description of the 1972 Act as a ‘conduit’ through which EU law passed into domestic law (para 65). But that conduit applies to the rights, obligations (etc) only ‘from time to time’ arising under the Treaties. As the Supreme Court recognised (at para 24), the Treaty of Lisbon (and A50, which it introduced into the TEU) is incorporated into UK law through the European Communities (Amendment) Act 2008. Thus, when the Treaties cease to apply to the UK, the rights and obligations of EU membership – including all the effects on domestic law set out in para 24 above – also cease.
32 This analysis is not contradicted by the rejection by the majority in Miller of the argument (including in the dissenting judgment of Lord Reed and in the academic opinions of Professor Finnis and others) that there remained a Prerogative power to notify (under A50). That (unsuccessful) argument was that the foreign relations Prerogative would not frustrate the 1972 Act as it provided a conduit for the application of EU law only for as long as the Treaties applied ‘from time to time’ on the international plane; and that within the Treaties was the right to withdraw. Their Lordships did not contradict the clear meaning of s 2 (1) of the Act – expressed in the conventional terms of legislation giving domestic effect to international obligations – that the Treaties remained a conduit for the domestic effect of EU law only for as long as those Treaties applied. Rather, it simply found that the means by which the UK could trigger a process leading to its inevitable (it was thought) withdrawal were restricted to the passage of primary legislation: notification would frustrate the purpose of the 1972 Act and the Prerogative could not be used to remove the rights that applied in domestic law through the conduit of the Act.
NO STATUTORY POWER
33 ‘Exit day’ is defined in s 20 (1) of the 2018 Act as 29 March 2019 at 11.00 p.m. Its importance in domestic legislation is that, were s 1 in force (which it is not), the 1992 Act would be repealed on exit day. It otherwise has the consequences set out above.
34 Section 20 of the 2018 Act provides for circumstances in which a Minister may ask for secondary legislation to be approved by both Houses of Parliament, amending ‘exit day. The relevant provisions of this section are as follows:
(3) Subsection (4) applies if the day or time on or at which the Treaties are to cease to apply to the United Kingdom in accordance with Article 50(3) of the Treaty on European Union is different from that specified in the definition of “exit day” in subsection (1).
(4) A Minister of the Crown may by regulations—
(a) amend the definition of “exit day” in subsection (1) to ensure that the day and time specified in the definition are the day and time that the Treaties are to cease to apply to the United Kingdom, and
(b) amend subsection (2) in consequence of any such amendment
(1) The sub-sections create a power to amend primary legislation, a so-called ‘Henry VIII’ clause.
(2) A Minister may only lay, both Houses of Parliament may only approve (through the affirmative resolution procedure) and the Minister may only (thereafter) make secondary legislation once there is already a ‘day and time’ that the Treaties ‘are’ to cease to apply in the UK. It must follow that this clause is only operative where, as a matter of EU and international law, the extension has already been agreed and become effective pursuant to A50. Thus, any regulations passed before the completion of the extension are void as a matter of domestic law. 
(3) It follows that the 2018 Act does not purport to create a statutory power for the Crown to apply and/or agree to an extension on behalf of the UK. The statutory power is limited to enabling amendment of legislation and has no lawful effect until, as a matter of EU and (because of the effect of the 1972 Act) domestic law, the continued application of the Treaties through EU membership has already been extended.
36 Moreover, neither the 2017 nor the 2018 Act confer an implied statutory power to extend A50 on the international plane.
37 The 2017 Act created a power of notification under A50 that was specific and narrowly confined. The language of the very short statute is not unclear or vaguely worded and does not allow for any construction other than its express meaning.
38 Section 20 (3) and (4) of the 2018 Act operates only once such power as there may be to extend is exercised lawfully. Further and alternatively, these sub-sections are ‘Henry VIII’ clauses allowing the modification of primary legislation. Such clauses may only be construed narrowly, not broadly, and only as an ‘exceptional’ course (see R (Public Law Project) v Lord Chancellor  UKSC 39 at para 27, applying McKiernon v Secretary of State for Social Security, The Times, November 1989, CA). There is simply no space for the implication of a statutory power into s 20(4) EUWA therefore faces an additional hurdle.
39 Of significance here is the finding of the Supreme Court in Miller that s 2 (1) of the 1972 Act (quoted above) did not and cannot have created a statutory ‘power’ to notify under A50 on the international plane, as such a power was ‘not one which would be given “legal effect or used in”, or which would be “enjoyed by the United Kingdom”’ (para 79). Similarly, the power of secondary legislation conferred by s 20 (1) are restricted to circumstances in which the date on which the Treaties cease to apply to the UK has already changed. They do not purport to affect what power there may be to extend A50, which necessarily must have been exercised before such secondary legislation could be put into effect.
NO PREROGATIVE POWER
The Crown may not legislate, create criminal offences or raise taxes
40 In Miller, the Supreme Court was concerned with rights that would be removed by the purported operation of the Royal Prerogative (purported because it was found to be in abeyance) and it was for that reason (in addition to the finding that A50 notification would frustrate the statutory scheme of the 1972 Act) that it determined that there was no Prerogative power to do so. While withdrawal from the EU undoubtedly does remove ‘rights’, it also removes what s 2 (1) of the 1972 Act described as ‘liabilities’, ‘obligations’ and ‘restrictions’. Aside from financial liabilities (itself a matter of constitutional significance given the control of Parliament over supply), the continued effect of EU law and the inability of the Westminster Parliament to legislate in contravention of it (under the domestic law provisions of the 1972 Act as well as pursuant to the UK’s international obligations) is undoubtedly both an obligation and a restriction (as summarised above).
41 In Miller, the Court distinguished the scheme of the 1972 Act from other acts of the Crown on the international plane. In the latter, the ‘dualist’ theory – which derives from Parliamentary sovereignty – provides that Prerogative acts on the international plane have no effect on domestic law (paras 56-58). Under the 1972 Act, however, executive acts may change domestic law and curtail the (otherwise) sovereign right of Parliament to legislate ( R v Secretary of State for Transport, Ex p Factortame Ltd (No 2)  1 AC 603 and (No 5)  1 AC 524, cited at para 60 of Miller).
42 While the rights the Supreme Court sought to protect from the unlawful use of the Prerogative were individual rights created by EU law, the 17th century development of constitutional principles restricting the Prerogative (on which the Supreme Court rightly relied) were an objection to the Crown’s right (in particular) to legislate, create criminal offences and raise taxation: from the Case of Proclamations ( EWHC KB J22) to the Bill of Rights 1689 and beyond.
43 In the former, Lord Coke (relying on the customs of the Realm from at least the reign of Henry IV expounded by Sir John Fortescue in De Laudibus Angliae Legum) found that:
‘…when authority and precedent is wanting, there is need of great consideration, before that any thing of novelty shall be established, and to provide that this be not against the law of the land: for I said, that the King cannot change any part of the common law, nor create any offence by his proclamation, which was not an offence before, without Parliament…
‘…also the law of England is divided into three parts, common law, statute law, and custom; but the King's proclamation is none of them: also malum aut est malum in se, aut prohibitum, that which is against common law is malum in se, malum prohibitum is such an offence as is prohibited by Act of Parliament, and not by proclamation.
44 Through the Bill of Rights, Parliament declared that the Crown may not:
‘…endeavour to subvert and extirpate… the Lawes and Liberties of this Kingdome… By Assumeing and Exerciseing a Power of Dispensing with and Suspending of Lawes and the Execution of Lawes without Consent of Parlyament…
‘By Levying Money for and to the Use of the Crowne by pretence of Prerogative for other time and in other manner then the same was granted by Parlyament…
‘And illegall and cruell Punishments inflicted.’
45 As the Supreme Court emphasised in Miller:
Parliamentary sovereignty is a fundamental principle of the UK constitution, as was conclusively established in the statutes referred to in para 41 above. It was famously summarised by Professor Dicey as meaning that Parliament has “the right to make or unmake any law whatsoever; and further, no person or body is recognised by the law as having a right to override or set aside the legislation of Parliament; - op cit, p 38. The legislative power of the Crown is today exercisable only through Parliament. This power is initiated by the laying of a Bill containing a proposed law before Parliament, and the Bill can only become a statute if it is passed (often with amendments) by Parliament (which normally but not always means both Houses of Parliament) and is then formally assented to by HM The Queen. Thus, Parliament, or more precisely the Crown in Parliament, lays down the law through statutes - or primary legislation as it is also known - and not in any other way.
…The Crown's administrative powers are now exercised by the executive, ie by ministers who are answerable to the UK Parliament. However, consistently with the principles established in the 17th century, the exercise of those powers must be compatible with legislation and the common law. Otherwise, ministers would be changing (or infringing) the law, which, as just explained, they cannot do. A classic statement of the position was given by Lord Parker of Waddington in The Zamora  2 AC 77, 90:
“The idea that the King in Council, or indeed any branch of the Executive, has power to prescribe or alter the law to be administered by Courts of law in this country is out of harmony with the principles of our Constitution. It is true that, under a number of modern statutes, various branches of the Executive have power to make rules having the force of statutes, but all such rules derive their validity from the statute which creates the power, and not from the executive body by which they are made. No one would contend that the prerogative involves any power to prescribe or alter the law administered in Courts of Common Law or Equity.”
46 The purported exercise of the Prerogative in extending A50 is, on one view, a more serious breach of the prohibition on the Crown to legislate than A50 Notification would have been. While notification would have affected rights granted by EU law through the conduit of the 1972 Act, the extension of the A50 period – for a potentially unlimited period – continues the curtailment of Parliamentary sovereignty that would otherwise end with the withdrawal of the United Kingdom from the European Union. It strikes at the heart of the abuse of the Crown’s power excoriated by Fortescue, Coke and the 1689 Convention Parliament.
47 Parliament, by granting the Prime Minister the power to notify, authorised the removal of the liabilities, obligations and restrictions imposed by the Treaties two years after notification; and for domestic law to revert to the status quo ante the 1972 Act, thereby restoring its sovereignty that was (temporarily) curtailed by that Act. Were there a Prerogative power to extend EU membership after the expiry of the initial A50 period, that power would require the continuance in domestic law of those liabilities, obligations and restrictions; and the continued curtailment of Parliamentary sovereignty. But for that act, domestic law would by the operation of the Notification have ceased to incorporate changes to EU law. This exercise of a purported Prerogative by the Prime Minister would thus, by executive fiat, cause legislation to be made, Parliament’s right to legislate to be restricted, criminal offences to be created and taxes to be raised. The Crown has never had such a Prerogative; and its purported exercise of it is unlawful and void.
No Prerogative power save where sanctioned by statute
48 At para 86 in Miller, the majority held that:
‘…the Royal Prerogative to make and unmake treaties, which operates wholly on the international plane, cannot be exercised in relation to the EU Treaties, at least in the absence of domestic sanction in appropriate statutory form. It follows that rather than the Secretary of State being able to rely on the absence in the 1972 Act of any exclusion of the Prerogative power to withdraw from the EU Treaties, the proper analysis is that, unless that Act [the ECA] positively created such a power in relation to those Treaties, it does not exist.’
49 So, while the Crown may still exercise Prerogative powers in relation to the Treaties (as also acknowledged in para 95), it may do so only as authorised by statute. At para 87, the Court considered whether the 1972 Act conferred a power of withdrawal and determined that it did not:
‘…Had the Bill which became the 1972 Act spelled out that ministers would be free to withdraw the United Kingdom from the EU Treaties, the implications of what Parliament was being asked to endorse would have been clear, and the courts would have so decided. But we must take the legislation as it is, and we cannot accept that, in Part I of the 1972 Act, Parliament “squarely confront[ed]” the notion that it was clothing ministers with the far-reaching and anomalous right to use a treaty-making power to remove an important source of domestic law and important domestic rights.
50 Similarly, Parliament could in the 2017 Act have ‘spelled out’ the power of the Crown not simply to notify but to ask for and agree to extend the A50 period. But it did not. Thus, in the absence of such statutory authority – particularly given that the Crown could otherwise request and agree to extensions on repeated occasions and/or of unrestricted duration – the Crown has no such power.
Frustration of the purpose of the 2017 and 2018 Acts
51 In Miller, the Supreme Court set out a digest of a further common law limitation on the Prerogative: namely that it may not frustrate the purpose of a statute or be exercised where a particular statutory scheme exists regulating the exercise of executive power:
 The Royal prerogative encompasses the residue of powers which remain vested in the Crown, and they are exercisable by ministers, provided that the exercise is consistent with Parliamentary legislation. In Burmah Oil Co (Burma Trading) Ltd v Lord Advocate , 101, Lord Reid explained that the Royal prerogative is a source of power which is “only available for a case not covered by statute”. Professor HWR Wade summarised the position in his introduction to the first edition of what is now Wade and Forsyth on Administrative Law (1961), p 13:
“[T]he residual prerogative is now confined to such matters as summoning and dissolving Parliament, declaring war and peace, regulating the armed forces in some respects, governing certain colonial territories, making treaties (though as such they cannot affect the rights of subjects), and conferring honours. The one drastic internal power of an administrative kind is the power to intern enemy aliens in time of war.”
 Thus, consistently with Parliamentary sovereignty, a prerogative power however well-established may be curtailed or abrogated by statute. Indeed, as Professor Wade explained, most of the powers which made up the Royal prerogative have been curtailed or abrogated in this way. The statutory curtailment or abrogation may be by express words or, as has been more common, by necessary implication. It is inherent in its residual nature that a prerogative power will be displaced in a field which becomes occupied by a corresponding power conferred or regulated by statute. This is what happened in the two leading 20th century cases on the topic, Attorney General v De Keyser's Royal Hotel Ltd and Fire Brigades Union cited above. As Lord Parmoor explained in De Keyser at p 575, when discussing the prerogative power to take a subject's property in time of war:
“The constitutional principle is that when the power of the Executive to interfere with the property or liberty of subjects has been placed under Parliamentary control, and directly regulated by statute, the Executive no longer derives its authority from the Royal Prerogative of the Crown but from Parliament, and that in exercising such authority the Executive is bound to observe the restrictions which Parliament has imposed in favour of the subject.”
 In Burmah Oil cited above, at p 101, Lord Reid described prerogative powers as a “relic of a past age”, but that description should not be understood as implying that the Royal prerogative is either anomalous or anachronistic. There are important areas of governmental activity which, today as in the past, are essential to the effective operation of the state and which are not covered, or at least not completely covered, by statute. Some of them, such as the conduct of diplomacy and war, are by their very nature at least normally best reserved to ministers just as much in modern times as in the past, as indeed Lord Reid himself recognised in Burmah Oil at p 100.
 Consistently with paras 44 to 46, and the passage quoted from Professor Wade in para 47 above, it is a fundamental principle of the UK constitution that, unless primary legislation permits it, the Royal prerogative does not enable ministers to change statute law or common law. As Lord Hoffmann observed in R (Bancoult) v Secretary of State for Foreign and Commonwealth Affairs (No 2) , para 44, “since the 17th century the prerogative has not empowered the Crown to change English common or statute law”. This is, of course, just as true in relation to Scottish, Welsh or Northern Irish law. Exercise of ministers' prerogative powers must therefore be consistent both with the common law as laid down by the courts and with statutes as enacted by Parliament.
 Further, ministers cannot frustrate the purpose of a statute or a statutory provision, for example by emptying it of content or preventing its effectual operation. Thus, ministers could not exercise prerogative powers at the international level to revoke the designation of Laker Airways under an aviation treaty as that would have rendered a licence granted under a statute useless: Laker Airways Ltd v Department of Trade stated that it was inappropriate for ministers to base their actions (or to invite the court to make any decision) on the basis of an anticipated repeal of a statutory provision as that would involve ministers (or the court) pre-empting Parliament's decision whether to enact that repeal.- see especially at pp 718-719 and 728 per Roskill LJ and Lawton LJ respectively. And in Fire Brigades Union cited above, at pp 551-552, Lord Browne-Wilkinson concluded that ministers could not exercise the prerogative power to set up a scheme of compensation for criminal injuries in such a way as to make a statutory scheme redundant, even though the statute in question was not yet in force. And, as already mentioned in para 35 above, he also
52 The Court distinguished cases where the exercise of the Prerogative changed the status of ‘a person, thing or activity’ (for example by declaration of war, which was permissible) from cases where its exercise ‘changed the law’ (para 53).
53 The 2017 Act did not merely give the Prime Minister a power to notify. The long title of the Act was:
‘An Act to confer power on the Prime Minister to notify, under Article 50(2) of the Treaty on European Union, the United Kingdom’s intention to withdraw from the EU’
54 Given that it was Parliament’s intention that the UK would withdraw from the EU, the Prime Minister had a discretion when, not whether, to notify. But whether or not the exercise of the power was discretionary, Parliament authorised an act which would, if exercised, lead inexorably to the consequences on domestic law outlined at para 24 above – the end of the curtailment by EU membership on Parliamentary sovereignty and the end of the EU’s powers to imposed legislation, criminal offences and demands of revenue on the UK. Parliament must be assumed to have legislated knowing that the consequence was that EU membership would end (absent an extension) not later than two years after notification, particularly given the express statutory reference to A50 in s 1 of the Act.
55 It has been submitted that the absence of a statutory power – in the 2017 Act or elsewhere – is sufficient for the court to determine that the Prime Minister’s purported agreement to the extension was void. Alternatively, such an act would frustrate the purpose and scheme of the 2017 Act. The power given by Parliament to the Prime Minister was limited to notification. Those powers could have extended to agreeing to an extension ‘on behalf of the [United Kingdom]’. But they did not.
56 The further means by which the date of the withdrawal of the UK from the EU could have been different from two years after notification was by the ratification of a withdrawal agreement by the UK and the EU. Yet the absence of reference to this in the 2017 Act is of no object, as any such withdrawal agreement could only have affected domestic law through further primary legislation (JH Rayner (Mincing Lane) v Department of Trade and Industry, supra). Such an agreement would otherwise only affect the UK’s international obligations; and its ratification would be through the Crown’s classic Prerogative of the conduct of foreign relations, in contradistinction to an extension of the A50 period, which would affect domestic law.
57 Finally, Parliament has since provided a statutory scheme, in the 2018 Act, for the UK’s withdrawal from the EU. While this scheme is intended to preserve the continuity of law after withdrawal (and while much of it is not in force) it was passed with the purpose of putting that withdrawal into effect in domestic law.
58 As has been set out, the Act does not merely define exit day but allows that date to be amended after (but only after) the A50 period has been extended. Yet, while Parliament could have provided for an executive power to agree to such an extension, it did not do so. The fact that ‘exit date’ could be extended cannot presuppose that a power already exists for HM Government to agree to extend the A50 period. Such an executive act would be wholly independent of the 2018 Act.
59 The lawfulness of any power to agree to an extension must be seen in the context of scheme of A50, which applies no limit to the duration of an extension or to the number of times it may be requested. It either exists or it does not. It is impossible – and undesirable – to attempt to draw a distinction between short extensions (such as those purportedly agreed by the Prime Minister) and longer ones; or between a first agreement to extend and subsequent agreements. The power either exists or it doesn’t; and each time it is exercised it has the same effect on domestic law – continuing the curtailment of Parliamentary sovereignty and the power of the EU to legislate, create offences and raise funds. Such a power would thereby frustrate the 2018 as much as the 2017 Act and any attempt to request or agree to an extension would, accordingly, be void.
EFFECT OF LACK OF POWER TO EXTEND
Under EU and international law
60 If the Prime Minister acted unlawfully by purporting to exercise Prerogative powers in seeking and agreeing to an extension of the A50 period, that act was void not merely as a matter of domestic law but as a matter of EU and international law.
61 It is an important feature of this matter that the unlawfulness of the powers purportedly exercised by the Prime Minister on the domestic plane will have no effect in domestic law if that exercise nevertheless binds the United Kingdom as a matter of EU law. The 1972 Act continues to be a conduit for EU law for as long as the Treaties apply to the UK; and the powers of HM Government and Parliament to make the Exit Day Regulations are dependent upon the A50 period ending on a different day to 29.3.2019. Thus, unless the unlawfulness of the Prime Minister’s actions voids them under EU law, they will still have domestic law consequences. For reasons developed below, it is submitted that acts by the Prime Minister within the EU bind the UK only where they are conducted in compliance with domestic law.
62 The unconstitutional and unattractive consequences of an unlawful act of a head of government potentially binding a Member State are themselves an important consideration in support of that contention. Three other submissions are made.
63 First, the scheme of A50 requires that all acts of the government of a withdrawing Member State are void unless done in accordance with the constitutional arrangements of the member state. While this is only expressly required of notification (in A50.1), the CJEU found in Wightman that notification may only be revoked in accordance with the constitutional requirements of a departing Member State (paras 37, 58, 66 and 67). The importance of the constitutionality of a Member State’s actions under A50 reflected the weight put upon the democratic process of those states by the EU (see para 67): and there can be little less democratic than an executive act, possibly exercised continuously, binding the UK to continued membership of the EU for indeterminate periods.
64 As has been submitted, the consequences of extension are considerable both for the EU and for the Member State concerned: for the period of the extension, they are identical to the consequences of revocation (and, while the CJEU in Wightman cautioned against the revocation of notification being used for tactical purposes prior to a renewed notification, there is no bar in EU law to a future notification after revocation). For the Member State, the obligations and liabilities summarised in para 24 above remain. For the EU, the Member State’s representation in all EU institutions remains, thereby diluting that of other Member States and providing that Member State with a veto over some decisions of the Council of the European Union and the European Council.
65 Secondly, the EU is a Union of States and Peoples founded upon democratic principles. Relations between governments within it are dependent upon the lawfulness of the acts of those governments under their domestic law, respect for which is inherent within the Treaties. Inter-governmental relations affecting the notification of withdrawal and extension of the A50 period are not the conduct of international relations between treaty making foreign powers nor even (save in respect of the negotiation of a withdrawal agreement) a treaty making process between current members of the EU. The application for and agreement to an extension is to be done between the UK and the Council ‘with the agreement of the Member State’. The Member State is not merely its government and its government may not act on its behalf save under its lawful authority. It would be inapt to treat the acts of governments of member states within such bodies as being comparable to the ‘apparent authority’ of governments when exercising treaty making powers on the international plane.
66 Thirdly, precedent in international law supports the Claimant’s contention that unconstitutional acts of a head of government (in the context of the UK, acts unlawful in public law terms) cannot bind a member state of a supranational organisation. In his opinion preceding the CJEU judgment in Wightman (ECLI:EU:C:2018:978), Advocate General Campes Sanchez Bordona gave an example of the unconstitutional act of a head of government within a supranational body being void as a matter of international law:
69. On 19 August 2009, the Government of Panama notified (43) its withdrawal from the Treaty Constituting the Central American Parliament and Other Political Bodies (‘Parlacen’), (44) citing in support of its position Article 54(b) of the VCLT. Faced with the refusal of the members of Parlacen, the Government of Panama requested the Panamanian National Assembly to approve Law 78, of 11 December 2011, which echoed the wording of that notification and proposed the annulment of the Panamanian instruments which ratified that Treaty. However, the Corte Suprema de Justicia de Panamá (Supreme Court of Justice, Panama) declared that law unconstitutional, in that it infringed Article 4 of the Panamanian Constitution (‘The Republic of Panama abides by the rules of International Law’), since the Parlacen Treaty did not include a clause expressly providing for withdrawal and that withdrawal was not feasible under Articles 54 and 56 of the VCLT. (45) As a result of that judgment, Panama’s withdrawal notification was revoked and that country resumed participating in Parlacen.
67 It was not suggested that Panama needed to be re-admitted to Parlacen: its notification of withdrawal was void ab initio in view of its government acting without constitutional authority. This principle applies, if anything, more to the relations between the UK and the EU. The EU is not merely an organisation of states but of peoples. It is a highly integrated supranational organisation with a directly elected law making assembly, whose laws override national laws and whose Court of Justice is the ultimate arbiter of that law. Where exercising powers at an inter-governmental level, governments may only act in accordance within their constitutional authority.
68 Consequently, in the event the Crown had no power to agree, the extension cannot have been made ‘with the agreement of the Member State concerned’ and the Treaties ceased to apply to the UK on 29.3.2019.
In domestic law
69 Parliament only had the power to make the Exit Day Regulations if, as a matter of international law, the date on which the Treaties ‘are to cease to apply… is different’ to 29.3.2019 (s 20 (3) of the 2018 Act). If the extension purportedly agreed by the Prime Minister before those Regulations were made (on 28.3.2019) was void, the date on which the Treaties would cease to apply was not different (as a matter of international law), Parliament would have had no power to make the Regulations and they were void.
70 The consequential effect on domestic law has been set out in paras 24 above. The limited parts of the 2018 Act in force would have come into effect on ‘exit day’ (11 pm on 29.3.2019) and the 1972 Act, while not repealed (s 1 of the 2018 Act not being in force) would cease to be a conduit for EU law, the Treaties having ceased to apply to the UK.
71 Because HM Government and Parliament have not (through secondary legislation) put the remaining important provisions of the 2018 Act into force, there would thereby be some uncertainty as to the status of EU Regulations that previously had effect under the 1972 Act. It is suggested that Directives incorporated by secondary legislation would continue to have effect given that such legislation was in accordance with the 1972 Act then in force. Regulations that came into effect while the Treaties applied to the UK might continue to remain law under the 1972 Act, which remains in force. That Act provided that Regulations had automatic effect while the Treaties applied to the UK and did not provide that their continued validity (in domestic law) was dependent upon continued EU membership. Alternatively, Parliament could pass primary legislation to put the 2018 Act provisions into force retrospectively.
72 However, none of the above consequences can or should stop the Court from determining this case under the correct legal principles. If the Prime Minister’s agreement to the extension of the A50 period was void, it was void whatever disruptive consequences that may have on UK law or otherwise. The Courts must enforce the rule of law, whatever the consequences.
73 The test for standing in judicial review proceedings is not high. In Walton v Scottish Ministers ( UKSC 44) the Supreme Court quoted with approval this finding of Lord Denning in Attorney-General of the Gambia v N'Jie ( AC 617, at 634):
“The words 'person aggrieved' are of wide import and should not be subjected to a restrictive interpretation. They do not include, of course, a mere busybody who is interfering in things which do not concern him: but they do include a person who has a genuine grievance because an order has been made which prejudicially affects his interests.”
74 Particularly pertinent to this case is the judgment of the Administrative Court in R (on the application of Save our Surgery Ltd) v Joint Committee of Primary Care Trusts ( EWHC 439 (Admin), ‘Save our Surgery’). There, Nicola Davis J found that a claimant had sufficient interest where it represented:
"…many individuals who have contributed financially in order to bring these proceedings. It includes individuals who have been or could be directly affected by the closure of the Leeds Unit and clinicians who work within the unit. Incorporation, following the intervention of the Charity Commission, was a proper means of allowing the interests of a substantial number of such persons to pursue this litigation"
75 In making this decision, the Court took into account that:
The majority, if not all of the individuals who have contributed to the fighting fund, together with the Directors of the claimant, would have a direct sufficient interest in their own right had they brought the claim as individuals… The adverse costs in litigation are such that no citizen of ordinary means would prudently contemplate bringing this litigation as an individual. Incorporation was and is the proper means of allowing the interests of a substantial number of persons who consider the defendant's decision to be unfair and unlawful to be jointly represented…
76 This case is being brought by a Political Party registered to participate in regulated democratic elections. In the 2014 EP elections it received around 125,000 votes. Moreover, this litigation is being crowd-funded and it is reasonable to suppose that a large proportion of its funders are citizens or residents of the UK with an interest in its membership of the EU. As in Save our Surgery, most if not all of the Claimant’s members would have standing were any one of them to pursue a claim individually; the costs and costs risks of such proceedings would be prohibitive for any of them individually; and it is reasonable for a corporation to litigate such proceedings. Indeed, there is if anything more reason for the Claimant to have standing as it has been a registered political party since 1999, twenty years before this challenge.
77 Given the initial requirement of permission, the Claimants rely with gratitude on the opinions and comments expressed in the public domain by the Rt Hon Sir Richard Aikens (a former lord justice of appeal speaking extra-judicially), in support of the contention that this claim is at least arguable:
(1) In an opinion article for ‘Briefings for Brexit’ published on 25.3.2019, before the extension came into effect; and
(2) In comments reported on 3.4.2019, after the start of the purported extension, in which he stated that “the way in which the extension was organised [was] 'highly unsatisfactory' and 'arguably illegal'” and that
‘If the argument... is correct, then it would mean that, under UK law, we left the EU last Friday at 11pm. The Treaties would no longer be binding and the UK would no longer be subject to EU law.’
'The argument obviously becomes much more important if there is any attempt at a longer "extension", but, logically, if the argument is correct, then any attempt at a further extension would be a legal nonsense as the UK would already be "out".'
78 Sir Richard’s article is attached as an annex to these submissions.
79 The attempt by the Prime Minister to exercise a prerogative power to extend EU membership continued was an attempt to continue, by executive fiat, the curtailment of Parliamentary sovereignty and the power of the EU to legislate, make criminal offences and raise funds. No such power exists, being contrary to fundamental principles of the common law, and her agreement to the extension was, accordingly, void.
80 Alternatively, the exercise of such a power would have frustrated the 2017 and 2018 Act and was void.
81 In consequence, the United Kingdom’s membership of the EU ended on 29.3.2019, since when the Treaties have ceased to apply to domestic law.
8th April, 2019
Field Court Chambers,
5 Field Court,
London WC1R 5EF
 It is unclear whether the Republic of Hungary exercised its vote, although it did not veto the decision to accept the Prime Minister’s request, purportedly on behalf of the United Kingdom, or the offer to extend the A50 period to the two alternative dates.
 Required wherever legislation may curtail Her Majesty’s Prerogative.
 Those in the three jurisdictions of England and Wales, Scotland and Northern Ireland.
 An argument has been raised that the draft SI could be put before both Houses of Parliament for affirmation before agreement was made to extend at the international level and the SI made by the Minister only after the date on which the Treaties ‘are’ to cease to apply was different to 29.3.2019. This argument is not made or developed here and would fall to be considered only as an alternative to the Claimant’s position: which is that only primary legislation could create a statutory power for HM Government to agree to an extension ‘on behalf of the United Kingdom’.
 I am indebted to Robert Craig, tutor in law at Durham University and the LSE, for his analysis of the statutory context, albeit that he comes to a different conclusion on the possible exercise of the Prerogative: R. Craig, ‘Can the Government Use the Royal Prerogative to Extend Article 50?’, U.K. Const. L. Blog (9th Jan. 2018): https://ukconstitutionallaw.org/2019/01/09/robert-craig-can-the-government-use-the-royal-Prerogative-to-extend-article-50/
 See paras 41 and 44
 When these submissions refer to ‘unconstitutional’ in the UK context, what is meant are acts of a constitutional nature that are unlawful on statutory and/or common law grounds and may thereby be voided by judicial review. Excluded from the term (as used here) are breaches of convention that might be described as ‘unconstitutional’ but are non-justiciable.
 Where a state may not invoke the fact that its consent to be bound by a treaty has been expressed in violation of a provision of its internal law regarding competence to conclude treaties as invalidating its consent unless that violation was manifest and concerned a rule of its internal law of fundamental importance: Vienna Convention on the Law of Treaties art 46 para 1
 The Advocate General includes a citation to the following article, which is in the Spanish language: http://www.parlacen.int/Actualidad/Actualidad/tabid/146/EntryId/369/Reintegro-de-Panama-al-PARLACEN.aspx