There appears to be a degree of uncertainty about the legal position concerning the extension of Article 50. Confusion seems to have arisen thanks to a combination of the way in which the European Council structured its decision to grant an extension and failure to understand the distinction and relationship between relevant provisions of European Union and UK law. In this post, I attempt to set out the legal position.

EU law

In recent weeks, a great deal of attention has focussed, unsurprisingly, on the UK Parliament.  We have, for instance, heard a lot about Parliament ‘ruling out’ certain options, most notably a no-deal Brexit. There have also been repeated references in the media and by politicians to the UK leaving the EU on 29 March 2019 because that date ‘is written into UK law’. (The UK law in question is the European Union (Withdrawal) Act 2018. We will come to that later.) All of this, however, misses the fundamental point: namely, that the UK’s membership of the EU turns not upon what domestic law says, but upon the position in international law — specifically, the EU Treaties.

The UK has been a member of the EU for the last half-century or so because it agreed to be a member, that agreement being recorded in and its terms set out in the EU Treaties. Article 50 of the Treaty on European Union (TEU) sets out the process by which a Member State may leave the Union. As is well know, that process was triggered by the UK roughly two years ago. At this stage in the process, it is Article 50(3) that is crucial:

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.

As is clear from this provision, the key issue is whether the EU Treaties continue to apply to the UK. For as long as they do, it is bound by them in international law; when the Treaties cease to apply, the UK ceases to be a Member State (albeit that transitional arrangements may apply, as they would if the Government’s deal were to be approved). This means that what UK law says is irrelevant to the question of EU membership. As such, neither a resolution passed by the House of Commons ‘ruling out’ a no-deal Brexit nor changing ‘exit day’ in domestic law can prevent the UK’s departure from the EU. That process is governed by EU law and, in particular, Article 50 TEU.

It is for this reason that last week’s European Council meeting was so crucial, and its decision to extend Article 50 vital. That decision is now recorded in the Official Journal of the European Union in European Council Decision (EU) 2019/476. The decision caters for two eventualities:

In the event that the Withdrawal Agreement is approved by the House of Commons by 29 March 2019 at the latest, the period provided for in Article 50(3) TEU is extended until 22 May 2019.

In the event that the Withdrawal Agreement is not approved by the House of Commons by 29 March 2019 at the latest, the period provided for in Article 50(3) TEU is extended until 12 April 2019. In that event, the United Kingdom will indicate a way forward before 12 April 2019, for consideration by the European Council.

This means that the window for approving the Withdrawal Agreement closes on 29 March if the Government wishes to benefit from the extension of the Article 50 period to 22 May. If the deal is not passed by the House of Commons by 29 March, then the UK will leave the EU with no deal on 12 April unless, by then, the European Council has agreed to a further extension or unless the UK has unilaterally revoked its notification under Article 50 (which it is entitled to do under EU law) so as to abort the Brexit process.

UK law

What, then, of UK law, and of the fact that ‘exit day’ is ‘written into’ domestic law? What, in particular, does this mean in terms of the role of the UK Parliament? This question is placed in sharp relief by an article in the Spectator’s Steerpike column today, which says that the magazine has been

passed a leaked briefing note from inside Number 10 which suggests the government would be able to brush Parliament aside and delay Brexit by Prime Ministerial edict. It is a confidential briefing note, offering answers to questions. The document asks if Theresa May has the ability to extend the Brexit deadline unilaterally, or if she first has to seek parliament’s approval, noting that Speaker John Bercow has said that the agreement of the House is necessary for any extension. But the briefing concludes that since MPs voted for the government to seek an extension on 14 March, that now: ‘Making the request and agreeing it with the EU is a matter for the government.’ Under this interpretation, Theresa May could declare – contrary to what she has been saying for the last two years and what everyone (including the Speaker) understood to be the law – that she does not need to consult parliament if she wants to agree an extension with the EU.

In unpacking this, it is important to keep two things distinct. First, there is the question of approaching the European Council for a(n) (further) extension. Second, and distinctly, there is the question of dealing with the domestic legal consequences of an extension. As far as approaching the European Council is concerned, it is clear that that is a matter for the Government. While it is strongly arguable that revoking Article 50 would require an Act of Parliament, the same does not go for extending Article 50. There is therefore little room for doubt that the Prime Minister acted lawfully by asking the European Council for an extension last week without having been authorised to do so by statute. In this sense, it is true that (as the Spectator puts it) the Prime Minister ‘does not need to consult Parliament’ about an extension.

The second and distinct point, however, concerns the domestic legal implications of successfully obtaining an extension, as the Prime Minister did last week. As a matter of EU law, the UK will not now leave the EU on 29 March; it will either leave on 12 April or 22 May, or on such other date as the UK and the European Council might unanimously agree. The problem, however, is that as things presently stand, ‘exit day’ is defined in the EU (Withdrawal) Act 2018 as 29 March 2019. Among other things, that Act provides that, on exit day, the European Communities Act 1972 — which gives effect to EU law in the UK, thereby enabling the UK to meet its legal obligations as a Member State — is to be repealed. Moreover, a great deal of secondary legislation has been made under the 2018 Act in order to adapt domestic law with effect from exit day, in order to ensure that domestic law can function adequately post-exit.

Although ‘exit day’ is defined by the 2018 Act, the Act enables Ministers to amend the definition of exit day, provided that the House of Commons and the House of Lords approve such an amendment. It is therefore likely that the Government will bring forward a statutory instrument very shortly providing for exit day to redefined in line with the European Council’s decision. This does not seem consistent with the view, expressed in the Spectator article, that the Prime Minister ‘does not need to consult Parliament’ in respect of extending Article 50.

It is true that, as a matter of EU law, consultation with Parliament is not needed before Article 50 can be extended. But it is necessary, if chaos is to be avoided, that domestic law should align with any extension. If the definition of ‘exit day’ were not to be redefined so as to reflect the extension, then one difficulty is that secondary legislation made under the 2018 Act would enter into force on 29 March, with the result that there would be two parallel sets of regulations in place — those deriving directly from EU law, and those made under the 2018 Act which would diverge from EU law. Faced with such a situation, a court would apply EU law in place of inconsistent domestic law, in line with the principle — which continues to apply while the UK is a Member State, including during an extension to the Article 50 period — that EU law takes priority over incompatible domestic law. But the existence of conflicting rules would nevertheless cause immense confusion.

A further apparent difficulty is that, as noted above, section 1 of the 2018 Act repeals the European Communities Act 1972 on exit day. This might appear to suggest that if exit day is not redefined, the 1972 Act will be repealed on 29 March, thus placing the UK in breach of its obligation under the EU Treaties to give domestic effect EU law. In fact, however, the Government has not yet brought section 1 of the 2018 Act into force. This means that even if exit day was not redefined, 29 March could come and go, and the 1972 Act would remain in place.


Where does this leave us? Following last week’s European Council decision, the EU Treaties will continue to apply to the UK after 29 March. They will continue to apply until 12 April (if the Withdrawal Agreement is not endorsed by the House of Commons by 29 March) or until 22 May (if the Withdrawal Agreement is approved by 29 March). This will be so whether or not the UK Parliament changes the definition of ‘exit day’ in the EU (Withdrawal) Act 2018. The Prime Minister acted lawfully by asking the European Council for an Article 50 extension, even though no Act of Parliament explicitly authorises her to do so, and it would be equally lawful for the Prime Minister to request a further extension.

What does this mean in terms of Parliament’s role over the coming days? Parliament should — even though it will not affect the Article 50 extension as a matter of EU law — align the definition of exit day in the 2018 Act with the decision reached by the European Council last week. If it does not do so, individuals will be faced with competing legal rules from 29 March — i.e. those deriving from still-relevant EU law and domestic rules made in the anticipation of Brexit occurring on 29 March. Such a situation would place individuals in an intolerable position and would create enormous confusion, even though ultimate the legal position — that the EU rules would take priority — is clear. It follows that it Parliament fails to approve the statutory instrument that the Government is likely to lay before it this week, so as to redefine ‘exit day’, this will not alter the (new) departure date of 12 April or 22 May, albeit that it would risk chaos in domestic law.

Parliament’s role is also clearly crucial in terms of deciding whether to approve the Withdrawal Agreement, since this will determine whether the Article 50 period runs until 12 April or 22 May. If Parliament does not approve the Withdrawal Agreement by 29 March, then it seems that it will have the further crucial role of shaping what it is that the Government puts to the European Council prior to 12 April, albeit that, as we have seen, the Government does not require parliamentary authorisation to seek a further extension should it be minded to do so. Finally, if the question of revoking the UK’s notification under Article 50 continues to rise up the political agenda, Parliament’s role will be critical, since it is relatively clear that this could only be accomplished by means of an Act of Parliament.

The UK’s membership of the European Union is determined by law — in particular, by the EU Treaties. One of the things that Brexiteers appear to dislike most about EU membership is the fact that the EU is a rules-based international order that limits domestic freedom of action, up to and including the enactment of primary legislation. Extricating the UK from the EU legal order and re-establishing ‘true’ parliamentary sovereignty is an article of faith for many Leavers. However, as Brexit (most likely still) looms, it remains the case that until the UK leaves, it continues to be a part of the EU legal order. Just as membership occurs on terms set by that legal order, so does departure. It is for this reason that the duration of any extension under Article 50 is a matter of EU law, not domestic law. And it is for this reason that whatever domestic law says about ‘exit day’, the UK will leave the EU in accordance with last week’s European Council decision, unless a further extension is agreed, or unless Parliament approves the Withdrawal Agreement or legislates to revoke Article 50. If the UK wishes to ‘take back control’, then so be it. But it can only do so in accordance with the law — in particular, and primarily, EU law.