UK Constitutional Law Association

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Aurel Sari: Biting the Bullet: Why the UK Is Free to Revoke Its Withdrawal Notification under Article 50 TEU

aurel-sari‘There is no going back.’ These were the words of Lord Pannick, uttered before the High Court in response to the question whether the United Kingdom could rescind its notification to withdraw from the European Union once issued under Article 50 TEU (Santos and M v Secretary of State for Exiting The European Union, uncorrected transcripts, p. 17). The claimants and the Government appear to agree on this point and accept that the UK cannot reverse its notification of withdrawal.

It is easy to see why this position should be attractive to both parties. For the Government, it means that once the notification has been issued in accordance with the UK’s constitutional requirements, it would be shielded from any subsequent domestic legal challenge. For the claimants, the irreversibility of the withdrawal notification is of ‘vital importance’ (uncorrected transcripts, p. 14). It is this irreversibility which, in their submission, pre-empts the powers of Parliament if the Government were to issue the notification without first obtaining the Parliament’s authorisation to do so.

The significance of this point was not lost on the Lord Chief Justice. He declined an invitation by counsel to assume that the withdrawal notification was irreversible and insisted that it was ‘absolutely essential’ for the Court to decide whether it was irrevocable or not (uncorrected transcripts, p. 192). In response, Lord Pannick confirmed that it was his position, as a matter of law, that there is no power to revoke the notification.

Earlier, Lord Pannick illustrated his position with the following analogy (uncorrected transcripts, p. 19):

I say my case is very simple. My case is that notification is the pulling of the trigger. And once you have pulled the trigger, the consequence follows. The bullet hits the target. It hits the target on the date specified in Article 50(3). The triggering leads to the consequence, inevitably leads to the consequence, as a matter of law, that the treatise cease to apply and that has a dramatic impact in domestic law.

Unfortunately for Lord Pannick, the analogy does not withstand closer scrutiny.

The applicable rules of interpretation

Whether a withdrawal notification is reversible or not is a question that turns on the interpretation of Article 50 TEU. Since Article 50 TEU forms part of an international agreement, its interpretation is governed not by English law, but by the rules of international law. Of course, as is well known, the Court of Justice of the European Union adopts a teleological approach to the interpretation of the EU’s founding Treaties which differs from the general rule of treaty interpretation laid down in Article 31 of the Vienna Convention on the Law of Treaties (VCLT). In particular, the Court lays greater emphasis on the aims and objectives of European integration than Article 31 VCLT might warrant (see Gardiner, Treaty Interpretation, pp. 136–137).

Leaving aside the longstanding doctrinal debates about the autonomous nature of the EU legal order, the fact remains that the founding Treaties of the EU are instruments of international law. It is therefore perfectly appropriate for a domestic court to construe Article 50 TEU by applying the rules of interpretation set out in the VCLT. In fact, this seems even more appropriate in the light of the subject matter of Article 50 TEU. It is no coincidence that the German Federal Constitutional Court interpreted Article 50 TEU against the background of the relevant provisions of the VCLT in its judgment in the Lisbon case (para 330).

What, then, are the applicable rules of interpretation? According to Article 31(1) VCLT,

A treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose.

Article 50(2) TEU stipulates that the Member State wishing to withdraw from the Union must notify the European Council of its intention. However, the text is silent as to whether a Member State subsequently may revoke its notification. In the absence of express terms, we have to consider whether an answer emerges from the text, context and the object and purpose of the treaty by implication.

The purpose of Article 50 TEU

According to Article 1 TEU,

By this Treaty, the HIGH CONTRACTING PARTIES establish among themselves a EUROPEAN UNION, hereinafter called “the Union”, on which the Member States confer competences to attain objectives they have in common.

It is difficult to find a more succinct statement of the object and purpose of the TEU: the establishment of an organisation upon which the Member States confer certain competences to attain certain shared objectives. These objectives are set out in greater detail in Article 3 TEU, while the scope of the EU’s competences is defined in Articles 3–6 of the Treaty on the Functioning of the European Union (TFEU). Article 5 TEU declares that the Union must act within the limits of the competences conferred upon it by the Member States and that competences not conferred upon the Union remain with the Member States. In Declaration 18 made appended to the Lisbon Treaty, the Member States recall these points and add that it is for them to increase or reduce the competences conferred upon the Union.

What emerges from these provisions is that the Union’s competences are based on the consent of its Member States and that the authority to increase or reduce these competences (sometimes described as Kompetenz-Kompetenz) remains firmly within their own hands. Article 50 TEU takes the principles of consent and conferral to their logical conclusion and confirms the right of a Member State to withdraw from the Union. In the words of the German Federal Constitutional Court, the ‘right to withdraw underlines the Member States’ sovereignty… If a Member State can withdraw based on a decision made on its own responsibility, the process of European integration is not irreversible.’ (Lisbon case, para 329). Against this background, we may conclude that the purpose of Article 50 TEU is to confirm in express terms the Member States’ ability to withdraw from the EU and to lay down the procedures for doing so.

The arguments against revoking the withdrawal

In his submissions before the High Court, Lord Pannick relied on three arguments to suggest that the UK would not be able to revoke its withdrawal notification once issued (uncorrected transcripts, p. 16–17):

Article 50 is deliberately designed to avoid any such consequence. There is no mention of a power to withdraw.  And the very possibility of a power to withdraw a notification would frustrate, again, Article 50(3), which sets out in the clearest possible terms, what the consequences are of giving the notification under Article 50(2).

It is convenient to consider these arguments in reverse order.

  1. Frustrating the procedures

First, Lord Pannick suggests that revoking the withdrawal notification would frustrate the consequences attached to the notification by Article 50(3) TEU. According to that provision,

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.

Once notified, the withdrawal is inevitable, says Lord Pannick. That is the point of his bullet analogy: once fired, the bullet has to hit its target, either upon the entry into force of the withdrawal agreement, two years after the date of withdrawal notification or at the end of any extension period agreed between the UK and the European Council. There are two flaws with this reasoning. First, the completion of the procedures described in paragraphs (2) and (3) of Article 50 TEU is conditional upon the withdrawal notification. There is no logical reason why that withdrawal notification may not be revoked before those procedures are completed. To use Lord Pannick’s analogy, nothing prevents the UK from firing a blank round. Second, the procedures listed in Article 50(3) TEU need not reach their end point. Article 50(2) TEU imposes an obligation on the Union to negotiate and conclude an agreement with the withdrawing Member State. No corresponding duty is imposed on the withdrawing Member State itself. At first sight, it might seem reasonable to assume that such a duty must be implied. However, for the purposes of the withdrawal agreement, the withdrawing State is essentially treated as a ‘third country’ (cf Article 218(1) TFEU), as evidenced by the fact that pursuant to Article 50(4) TEU, the withdrawing State shall not participate in the discussions or decisions by the European Council or Council concerning the negotiation and conclusion of the withdrawal agreement. Consequently, it would be absurd if the withdrawing Member State were thought to be bound by the principle of sincere cooperation under Article 4(3) TEU in these matters. In any event, the terms of Article 50(3) TEU make clear that at most, the withdrawing Member State is under an obligation to negotiate, but not necessarily conclude, a withdrawal agreement with the EU (in other words, the duty is for a pactum de negotiando, not a pactum de contrahendo). This is so because Article 50(3) TEU envisages that the withdrawal agreement may fail to enter into force at all, which is precisely why it provides for the two-year time period as a fall-back solution. However, that two-year time period may be extended by the mutual agreement of the withdrawing Member State and the European Council. The extension is not subject to any conditions. Consequently, the two sides may agree to an indefinite extension of the two-year period if they so wish. To use the bullet analogy again, the target may keep on moving indefinitely and the bullet may never hit home.

Notifying an intention to withdraw from the Union does not necessarily mean that the procedures triggered thereby have to be completed. Nor do these procedures inevitably have to lead to the termination of the applicability of the Treaties to the withdrawing Member States.

  1. No express power to revoke

Lord Pannick also relies on the fact that Article 50 TEU does not provide for the power to revoke the withdrawal notification in express terms. This argument is unconvincing. The competences of the EU depend on the consent of the Member States. Competences not conferred upon the EU remain with the Member States. Consequently, in so far as Article 50 TEU recognises the unilateral right of a Member State to withdraw its consent, that withdrawal can only be subject to those conditions which are expressly stipulated in Article 50 TEU. Put differently, the burden of proof is not on the withdrawing Member State to demonstrate that it has the legal capacity and authority to retract its withdrawal notification, but on the EU or its remaining Member States to show that it lacks that capacity.

At this point, it is once again necessary to recall that the Treaties are instruments of international law. As the European Court of Justice has acknowledged, the EU must respect international law in the exercise of its powers (Case C-286/90, Poulsen and Diva, para. 9). Pursuant to Article 68 VCLT, a notification to withdraw from a treaty in accordance with its provisions may be revoked ‘at any time’ before the notification takes effect. In the present case, this means that the UK would be able to revoke its withdrawal notification before the withdrawal agreement it may conclude with the Union enters into effect or before the two-year time period or the extension period agreed with the European Council runs out. The EU is not a party to the VCLT and as such it is not directly bound by Article 68 VCLT. Whether the rule forms part of customary international law, which would be binding on the EU as such, is subject to debate. However, it is worth noting that the International Law Commission, which drafted what later became Article 68 VCLT, took the view that ‘the right to revoke the notice is really implicit in the fact that it is not to become effective until a certain date’ (Draft Articles on the Law of Treaties with Commentaries, p. 264). This point applies with full force to Article 50 TEU.

State practice offers several examples of States revoking their decision to terminate their membership in an international organization, though the exact legal characterisation of some of these examples is open to discussion (see Wessel, You Can Check Out Any Time You Like, But Can You Really Leave?, p. 6). Nevertheless, the practice of the International Labour Organisation in particular suggests that the possibility to retract a withdrawal notice before it takes effect is accepted. It is also useful to point out that States may withdraw their intent to be bound by an international agreement, as the United States did in relation to the Rome Statute, or withdraw their application to become members of an international organisation, as Switzerland recently did in relation to the EU. Of course, one should be careful not to read too much into these examples, even by way of analogy. However, they do underline that States enjoy a wide measure of discretion to withdraw instruments and notifications they make in relation to treaty actions.

  1. The design of Article 50 TEU

Finally, Lord Pannick argues that Article 50 TEU was deliberately designed to avoid the possibility that a Member State might revoke its withdrawal notice. There is no evidence to support this view. The preparatory work of the intergovernmental conference which drew up the Treaty of Lisbon is not in the public domain. However, Article 50 TEU reproduces verbatim, subject only to minor editorial changes, Article I-60 of the Treaty establishing a Constitution for Europe. The negotiating history of that provision establishes very clearly that the right to withdraw from the Union was intended to be unilateral. Amendments attempting to tie this right to substantive conditions or to the successful conclusion of a withdrawal agreement were rejected (see CONV 672/03, pp. 10–12). As a note from the Praesidium of the European Convention explained, ‘it was felt that such an agreement should not constitute a condition for withdrawal so as not to void the concept of voluntary withdrawal of its substance’ (CONV 648/03, p. 9). This desire was reflected in the very title of Article I-60, which read ‘Voluntary withdrawal from the Union’.

The significance of this negotiating history is that it fully confirms the interpretation and conclusions reached earlier. The unilateral nature of the right to withdraw means that it is for the United Kingdom to decide both when to notify the European Council of its intention to withdraw and whether or not to revoke that notification. This position may please neither the claimants nor the defendant, but this is where the law stands.

Aurel Sari is a Senior Lecturer in Law at the University of Exeter, specializing in public international law. His work focuses mainly on questions of operational law, including the law of armed conflict, the legal status of foreign armed forces and the application of human rights law in deployed operations. He is a Fellow of the Allied Rapid Reaction Corps.

(Suggested citation: A. Sari, ‘Biting the Bullet: Why the UK Is Free to Revoke Its Withdrawal Notification under Article 50 TEU’, U.K. Const. L. Blog (17th Oct 2016) (available at

26 comments on “Aurel Sari: Biting the Bullet: Why the UK Is Free to Revoke Its Withdrawal Notification under Article 50 TEU

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  2. Dr Mike Tremblay
    October 17, 2016

    Your make the point that the treaties are subject to international law. Surely the only treaty that was strictly international was the one establishing the EU in the first place. When a country joins, they take on the acquis communautaire which in effect I think converts the arrangements from international law to internal matters of the EU itself.

    After that, given the supranational nature of the EU and subsequent treaties, they strike me more as intergovernmental agreements set within the confines of supranational EU law. I suspect that the use of the word ‘treaty’ is a misnomer. If it were otherwise, wouldn’t the all this EU law be subject to review outside the EU?

    What sets the EU apart from otherwise international treaties is the existence of the supranational law and the ECJ’s existence itself, coupled with a Parliament elected from universal suffrage from European citizens. Doesn’t sound quite like a treaty to me, sounds more like a constitution. (Duck test)

    Although the following invokes the word ‘federal’, surely agreements in federal-type systems, e.g. Canadian provinces/federal government, US states/federal government, (and so on: German Laender, Australian states), and indeed UK countries, are not subject to international law, are they? So the UK is really up the creek on this one.

    What do you think?

  3. Mike Fearon
    October 17, 2016

    Very well reasoned. I have previously suggested, in response to Barber et Al, that the issue illustrated by the “moving target” analogy, inter alia, may well be relevant in considering whether the ECA is necessarily nugated by a Notice under Article 50. This contribution is, in my view, a deeper and sounder analysis of the overall legal framework within which a Notice should be considered.

  4. Wolter Joosse
    October 17, 2016

    It is with interest that I read Mr Sari’s submission. However there are some obvious flaws in his reasoning. An International Treaty is only binding on the people of the State entering into that Treaty, if and only if, the Treaty has been re-enacted by its own Parliament. In so doing it becomes domestic law and binding. the UK Parliament is made up, in part, of Members who are the elected representatives of the people. Those Members of Parliament enjoy therefore only delegated authority. As such they could never claim to have a mandate to vote or act against the interest of their electors.

    The authority for the UK to join the EU derived from the result of a referendum. It was this approval of the people that provided the legal mandate to join. Equally the referendum result that expressed the will of the UK people to leave the EU is binding and cannot be revoked lawfully by any Parliament or Government. The will of the people rules supreme. The people of the UK have voted to leave the EU and the result is therefore irrevocable and binding. It appears that Mr Sari is confused by the fact that the withdrawal of the EU is not instant upon notification. But please it should be clear to all, that a period of time must be prescribed in order to allow for an orderly departure that allows time for the parting parties to formulate alternative arrangements. There are so many existing arrangements to untangle.

    It is also interesting that Mr sari wishes to rely on international law but overlooks the inviolable natural right to self determination of all people. Applying this natural right, it becomes clear that the referendum result must be obeyed and no section of the EU Treaty could possibly violate the will of the UK people, and they don’t.

    Lord Pannick is correct in his statement that there is no going back, the people have voted and withdrawal from the EU must therefore follow as a direct consequence of that vote.

  5. David Scott
    October 17, 2016

    Great post Aurel, thank you.

    On a slightly different note, how do you see the domestic legality of a Government-led withdrawal interacting with the VCLT’s procedure for withdrawal, and specifically the authorisation of state representatives under Article 67?

    So lets say that the Government loses its case at the High Court, but forges on ahead without Parliamentary approval. Domestically it would be, I imagine, very difficult to put the genie back in the bottle, if that notification is accepted by the EU. But would there be leeway to argue that a domestically illegal notification would be insufficient for the purposes of the VCLT – that the Head of State would in effect lose its “full powers”?

    • David Scott
      October 17, 2016

      Ah, I overlooked Article 50(1). A silly blunder.

      I wonder how such a ruling would affect the UK debate around the ECHR, however. I imagine a finding that Parliamentary approval would be needed for Brexit would be similarly applicable to withdrawal from the ECHR. But Article 58 of the ECHR contains no such requirement of domestic constitutional approval. Would the Government have more leeway here to act unilaterally and/or would there be more space for an argument under the VCLT?

  6. Peter Brunnen
    October 17, 2016

    This is extremely and remarkably well presented. It is also well balanced and keeps to the point. Quite a few people would have a better understanding of the issues at hand if they read this.

  7. Alex D-F
    October 17, 2016

    Re: “There is no logical reason why that withdrawal notification may not be revoked before those procedures are completed.”; and “Notifying an intention to withdraw from the Union does not necessarily mean that the procedures triggered thereby have to be completed.” –
    These interpretations seem to me incompatible with the wording of Article 50(3) which states that the Treaties will cease to apply to the relevant Member State in a given time after the notification, i.e. whether or not the notification is withdrawn. So it’s not a blank round. Time waits for no man, as is well known.

  8. Sam Lucas
    October 18, 2016

    Nonsense. Art 50 covers the matter, general international law is ousted (a fortiori given that the EU is not bound by the VCLT). Art 50 does not cover the question of revocation explictly, but it plain that the purpose of Art 50 is to protect the rights of the EU-27 and the EU’s own institutions, not the rights of the State that wants to leave. That is best achieved by stopping a State notifying, forcing costly negotiating and then reversing its notification. Pannick’s bullet analogy is spot on.

  9. Endorendil
    October 18, 2016

    I don’t think the UK could expect to stay if it tried this. After creating huge costs, considerable instability and no small amount of hostility, neither the UK public not the EU partners would allow it. It also would render article 50 not fit for purpose as the UK could simply give notification again and circumvent the time limit for negotiations.

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  20. Coventry Man
    January 17, 2017

    Reblogged this on Coventry View and commented:
    Not my normal area of interest, but a very good piece here by Aurel Sari of the University of Exeter on whether an Art 50 notice can be revoked.

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  24. Jono
    June 18, 2017

    Interesting “mental masturbation” only… as the EU (let alone France) is not a signatory to the VCLT and therefore the argument is moot. It has no binding effect in the ECJ (or upon the ECJ’s interpretation of the EU treaties) at ALL.

    Whence, the ECJ is free to adopt its own interpretation of A50 free from the doctrinal constraints of (as here) a non-binding treaty. Indeed, the fact that the EU is NOT a signatory allows the real argument that therefore there is no expressed intention to so be bound.

    —-> In such regards, that point is underscored given case C-286/90, Poulsen and Diva, at §9 is inapposite. That case, indeed that para, as made clear by §10 op.cit., correctly referred to UNCLOS to which the European Union IS indeed a signatory. Cf., the position viz. the EU and the VCLT.

    BTW, I have pleaded law in both chambers of the ECJ.

  25. Rosski
    June 26, 2018

    Not wishing to disagree with an occupant of the illustrious Amory Building but as I read this I had a very uneasy feeling that too many assumptions were being made. Having read the comments I would agree that Art. 50 is a one-way street.

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