A group of Conservative MPs — including Suella Braverman, Bill Cash and David Jones — have written to the Prime Minister arguing that the UK Government acted unlawfully by obtaining an extension to the Article 50 period without (in their view) due reference to Parliament. Their argument centres upon the way in which the definition of ‘exit day’ in the European Union (Withdrawal) Act 2018 (EUWA) interacts with the date on which the UK will leave the European Union under EU law. As is well known, the UK Government and the European Council agreed last week that the date of the UK’s departure from the EU should be changed from 29 March 2019 to either 12 April or 22 May (depending on whether the Withdrawal Agreement is approved by the House of Commons by 29 March). Braverman et al contend that the UK Government had no legal authority to enter into such an agreement: doing so without first securing the amendment of ‘exit day’ in domestic law, they say, means that the Government was acting incompatibly with the EUWA.

The MPs do not dispute that there could be circumstances in which the UK Government would have authority to seek an Article 50 extension, but they contend that its power to do so cannot be exercised unless ‘exit day’ has first been changed in domestic law. It is unclear whether they think that the Government’s power to seek an Article 50 extension in such circumstances would take the form of a prerogative power or an implied statutory power. Either way, however, the key question is whether their argument as regards the requisite sequencing is correct. In other words, are they right to contend that ‘exit day’ must first be changed in domestic law, and that only then can the Government exercise its power to seek an Article 50 extension? Or did the Government act lawfully adopting the reverse approach to sequencing — i.e. obtaining an Article 50 extension and then laying a statutory instrument before Parliament to amend ‘exit day’?

Braverman et al note that the power to amend ‘exit day’ can, according to schedule 7, paragraph 14 of the EUWA, only be exercised via a statutory instrument ‘a draft of [which] has been laid before, and approved by a resolution of, each House of Parliament’. The MPs contend that this means that the Government should have laid before Parliament a draft statutory instrument, setting out the revised ‘exit day’, and secured parliamentary approval for it before seeking an Article 50 extension from the European Council. This, they say, would have ensured that Parliament was not presented with a fait accompli, their view being that that is now precisely what Parliament is being presented with, given that the date of the UK’s departure from the EU has now been changed in EU law thanks to the European Council’s decision of last week.

However, there is a problem with the central argument put forward by Braverman et al. The problem becomes apparent when the power to change ‘exit day’ is examined closely. That power is set out in section 20(4) of the EUWA. It provides that ‘[a] Minister of the Crown may by regulations … amend the definition of “exit day” … 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’. If the MPs’ view were adopted, the statutory instrument would have to be made prior to Article 50 being extended. This would mean that when the instrument was made, it would stipulate a date for ‘exit day’ different from the date on which (at that time) the EU Treaties would cease to apply. Say, for instance, that in early March — and, importantly, prior to the meeting of the European Council — Parliament had approved a statutory instrument redefining ‘exit day’ as 12 April. There would, at the time the instrument was made, have been a mismatch between ‘exit day’ (as redefined) and (in the words of section 20(4)) the ‘time that the Treaties are to cease to apply to the UK’, since the latter would have remained 29 March pending a possible (but far from certain) subsequent decision by the European Council to extend Article 50. The upshot is that the statutory instrument, when made, would have been ultra vires. Section 20(4) allows ‘exit day’ to be changed in order to align it with the ‘day and time that the Treaties are to cease to apply’ — not the day and time that the Government hopes the European Council will agree to at a future meeting.  

This analysis points us towards the correct interpretation of the power to redefine ‘exit day’, and of the sequencing envisaged by the EUWA. The power to redefine ‘exit day’ only arises if the date on which the EU Treaties are to cease to apply to the UK has already been changed, by means of an Article 50 extension, such that it no longer aligns with the definition of ‘exit day’ set out in section 20(1) of the EUWA. As soon as such a misalignment occurs — that is, as soon as the European Council formally decides, with the UK Government’s agreement, to extend Article 50 — the power to make a statutory instrument redefining ‘exit day’ arises. But until the date of the UK’s departure from the EU has been altered under Article 50, the power to change ‘exit day’ in domestic law does not arise. The argument put forward by Braverman et al thus fails, and the Government can be seen to have acted lawfully by first using its prerogative power to obtain an Article 50 extension — the existence of such a power being compatible with the EUWA, which, as we have seen, clearly contemplates its exercise — and subsequently asking Parliament to approve a statutory instrument amending ‘exit day’.