Article 50, the Supreme Court judgment in Miller and why the question of revocability still matters – Rose Slowe

25 January 2017 by

England Europe

With the Supreme Court having ruled yesterday that Parliament must have a say in the triggering of Article 50 TEU, the ensuing debate regarding the process for exiting the EU will undoubtedly revolve around what is politically considered the most desirable ‘type’ of Brexit, and whether MPs can restrict the government’s negotiation position. This post puts forward the hypothesis that such debates may become irrelevant because, in the event that negotiations fail, the UK has no guaranteed input on the terms of its withdrawal from the EU. At the heart of this problem is the still unanswered question whether an Article 50 notification is revocable.

In R (on the application of Miller and another) v Secretary of State for Exiting the European Union [2017] UKSC 5, the Supreme Court rejected the government’s appeal and upheld the High Court’s ruling that the royal prerogative cannot be relied on to trigger Article 50 (see yesterday’s post on this blog which summarised the court’s judgment).  Rather than reliance on executive power, an Act of Parliament is required to authorise ministers to give notice of the UK’s decision to withdraw from the EU. This is based on the premise that such notification under Article 50(2) would inevitably, and unavoidably, have a direct effect on UK citizens’ rights by ultimately withdrawing the UK from the EU. However, this assumption warrants exploration.

The irrevocability of Article 50 was not raised before the Supreme Court as an issue requiring determination and the Court chose to proceed on the parties’ agreed assumption of irrevocability. The failure to raise or address the issue was indisputably politically motivated as opposed to stemming from an absolute consensus on the interpretation of Article 50. If adjudicated, as the domestic court of last resort, the Supreme Court would have been obligated to refer the question of revocability to the ECJ for determination, pursuant to the Article 267 TFEU preliminary reference procedure. The political backlash against the EU judiciary meddling in the manner by which the UK withdrew from the Union would have undoubtedly been immense. Unfortunately, the omission of an Article 267 reference regarding the revocability of Article 50 has not only thwarted the very purpose of the preliminary reference procedure by opening the risk of bifurcation in domestic interpretation, it has also missed an important opportunity to obtain legal certainty.

Article 50’s ‘assumed’ irrevocability is far from uncontentious. While the assumption appears to stem from a strict textual interpretation of Article 50(3), which specifies that ‘The treaties shall cease to apply to the State in question… two years after the notification referred in paragraph 2’ (emphasis added), with only an option for bilateral extension of the period of negotiation provided, compelling counter arguments have been put forward in legal scholarship. Professor Closa, for example, has raised a number of formal and substantive objections to the assumption of Article 50’s irrevocability, the most compelling drawing on a comparative assessment of international law and practice under which a withdrawing state is bestowed a ‘cooling off period’ allowing it to change its decision. Lord Kerr of Kinlochard, the drafter of the Article 50 provision, has also attested to its revocability. Further, Donald Tusk, the President of the European Council, has asserted, in his political capacity, that upon conclusion of the Article 50 negotiation process the status quo could be maintained, meaning that, if the UK was not happy with the agreed terms of Brexit, it could opt to continue to be a member of the EU.

Whether this decision to maintain membership status could be unilaterally reached by the UK as a matter of EU law is of huge constitutional significance at the domestic level. The Miller case deliberated whether the Government could rely on the royal prerogative to trigger Article 50, assuming this will inevitably, and unavoidably, have a direct effect on UK citizens’ rights by ultimately withdrawing the UK from the EU. However, if Article 50 was revocable, and the Government could accordingly issue notice under Article 50(2) without the inevitability of Brexit, the ruling would no longer withstand scrutiny. If the UK was able to issue notice and engage in negotiation with the European Council, put the negotiated terms of the UK’s withdrawal before Parliament for approval, and maintain the status quo if rejected, the Government could rely on its royal prerogative to issue notice under Article 50(2) and go to the negotiation table, with Parliament still able to have a final say on whether the UK ultimately withdrew from the EU on the terms offered. Accordingly, issuing notice under Article 50(2) would not, per se¸ alter any domestic law, and, as such, no Act of Parliament would be required to trigger it.

If we proceed, as the Supreme Court did, on the assumption that notice under Article 50(2) is indeed irrevocable, then the impact of issuing such notice must be explored further. Hypothetically, what if Parliament reached the decision that only partial withdrawal from the EU was desirable; for example, continued access to the single market or ‘soft Brexit’ to use the colloquial term in political discourse. As this will be a matter for negotiation with the European Council, the decision to withdraw on such terms cannot be made prior to notice under Article 50(2) having been issued. Note ought to be made here of the UK’s negligible negotiation power pursuant to Article 50(3). If it does not accept the terms offered, after two years it is stripped of member state status and ousted from the EU with no guarantee of a future relationship of any form. This ‘absolute Brexit’ is the default outcome of activating the Article 50 withdrawal process. In other words, a decision to trigger Article 50 would ultimately be a decision to accept absolute withdrawal if no better option is made available.

Legally, Parliament is not obligated to bestow the government competence to issue notice under Article 50(2). The referendum of 23 June 2016 was not legally binding, despite Parliament’s ability to have drafted it in a way which would have rendered it such. Further, it did not specify what ‘type’ of Brexit was on the ballot. When fulfilling its duty in our parliamentary democracy, acting in the best interests of all citizens and not just in respect of the wishes of those eligible to vote, Parliament must be fully aware that in bestowing ministers a mandate to trigger Article 50 it is endorsing absolute Brexit as a default result.

Article 50(1) requires a member state to ‘decide to withdrawal membership in accordance with its own constitutional requirements’. The Supreme Court has ruled that UK constitutional law necessitates Parliament’s approval before Article 50 can be triggered. This approval must take the form of consent to absolute withdrawal from the EU as this is the default outcome of the negotiation process. Any notice issued under Article 50(2) without such Parliamentary endorsement would arguably be void at both the supranational and domestic level for reason of constitutional incompliance. As such, Parliament has been left with just one decision resting on its shoulders: absolute Brexit or not.

Rose Slowe is a research intern at the Bingham Centre for the Rule of Law.  She has a particular interest in European human rights law, and is the co-author of a book on that subject which is due to be published by CUP later this year.


  1. Violet says:

    Wait! Did they change their minds or there are some people that are thinking it was wrong to vote for Brexit? Looking for an escape!

  2. ObiterJ says:

    I also think that the question of the revocability of Art 50 ought to have been determined. This may be of interest:

  3. Matt Flaherty says:

    Would it be possible for a party to sue the government or otherwise prompt a judicial review of the decision not to argue as to the revocability of the notice? It seems to me that Parliament is being denied vital information on the consequences of a vote it is about to conduct. There should be legal certainty on the effect of triggering Article 50 before we engage the legislative process, and that can only come from Europe.

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