UK Constitutional Law Association

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Philip Allott: Fundamental Legal Aspects of UK Withdrawal from the EU: Eight Stages on the Way to a New Relationship

philip-allottThe exceptional complexity of the legal aspects of UK withdrawal from the EU is due to the fact that it involves the interaction of three legal systems – international law, EU law and national law. The constitution of the EU is contained in treaties, taking effect under international law. EU law is made and administered by three classic organs of a constitution – legislative, executive and judicial. EU law is an external source of law integrated into the national legal systems of the member states. It can override national law in case of conflict.

It follows that the legal aspect of each stage of constructing a new legal relationship between the UK and the EU must be examined separately, in the light of law coming from the three interacting legal systems.

1. Conservative Party General Election Manifesto, May 2015, page 72

‘It will be a fundamental principle of a future Conservative Government that membership of the European Union depends on the consent of the British people – and in recent years that consent has worn wafer-thin. That’s why, after the election, we will negotiate a new settlement for Britain in Europe, and then ask the British people whether they want to stay in the EU on this reformed basis or leave. David Cameron has committed that he will only lead a government that offers an in-out referendum. We will hold that in-out referendum before the end of 2017 and respect the outcome.’

An election manifesto is not legally binding. On 20 February 2016 the Prime Minister announced that he had reached agreement with the EU on a ‘new settlement’ for Britain in Europe.

2. European Union Referendum Act 2015 (17 December 2015), sec. 1

‘(1) A referendum is to be held on whether the United Kingdom should remain a member of the European Union…  (4) The question that is to appear on the ballot papers is— “Should the United Kingdom remain a member of the European Union or leave the European Union?”

This is the statutory basis for holding a referendum.  The Act does not specify the legal effect of the outcome of the referendum.  Section 2 identifies those entitled to vote in the referendum and, by implication, those excluded from voting.

3. Referendum (23 June 2016). Electorate: 46.5 million.  Turnout: 72.2%.  Leave: 51.9%.  Remain: 48.1%

4. Treaty on European Union (Consolidated Version, 2009), Article 50 (incorporated from the Lisbon Treaty, 2007)

(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…

(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.

Eight points should be noted.

(a) Article 50 governs the withdrawal process as a whole. It is a treaty provision under international law, and a provision of EU law, and a part of UK law.

(b) The notification to the European Council is of an intention to withdraw. It is not a notification of withdrawal.

(c) The EU Council would draw up ‘guidelines’ for the negotiation of the withdrawal agreement. They are the equivalent of ‘instructions’ to a delegation in traditional diplomatic practice. EU Council guidelines are normally very detailed, and their drafting can be a lengthy and highly animated process.

(d) The UK would not take part in drawing up the Council guidelines. To enable the Council to agree them, it must have some idea of what the future relationship of the UK to the EU might be. Article 50 says that the agreement with the EU takes account of the framework for the UK’s future relationship. This means that there would be some prior interaction between the UK and the EU before the Council can draw up the guidelines for the main negotiation, and before the actual negotiation of the withdrawal agreement can begin.

(e) Withdrawal takes place automatically two years after the date of notification, if a withdrawal agreement has not entered into force by that date, unless the EU and the UK decide otherwise.  In the case of a member state such as the UK, the EU and the UK would surely so decide.

(f) Article 50 does not say if the notification of intention to withdraw can be withdrawn at any time.  The EU Council would no doubt accept such a withdrawal of the notification.

(g) The European Court of Justice has jurisdiction over the implementation of Article 50.

5. Decision to give notification of intention to withdraw

Seven points should be noted.

(a) Article 50 says that ‘a Member State may decide…’ and ‘[that] Member State shall notify…’ (italics added). The first is a legal power. The second is a legal obligation. It is normal international practice for the executive branch of the national government to express externally a decision to exercise a power or to carry out a duty under a treaty. The process for enabling the executive branch to do so is a matter of national constitutional law and practice.

(b) In the UK, the power of the executive branch to exercise a public power may arise under an Act of Parliament, the common-law or EU law, the three sources of law in this country. Where there is no legislation conferring on the executive branch a power to give a notification of withdrawal, the authority can only arise under the common-law or EU law.

(c) The common-law recognises certain inherent inherited powers that may be exercised by the executive branch. It is no longer appropriate to refer to these powers as the Royal Prerogative, except as a way of indicating their historical origin. They can be abridged or abolished by Act of Parliament, and often have been. The courts determine their existence and their content at any given time.

(d) The expression ‘parliamentary sovereignty’ is misleading and should be avoided. The ultimate principle of the British constitution is the Rule of Law, brilliantly identified as such by A.V. Dicey in 1885 from a study of the whole course of our constitutional history. All public power is subject to the law as determined and enforced by the courts. He spoke of the ‘supremacy of Parliament’ because Acts of Parliament override the common law. Parliament does not have an inherent non-statutory legal authority over the other two leading organs of the constitution, the Government and the courts.  All three are involved in a complex system of checks-and-balances.

(e) On a number of occasions, Parliament has altered its own powers by its own act – the Bill of Rights, the Parliament Acts, the Statute of Westminster, and the European Communities Act. The courts have recognised and enforced those alterations. Acts of Parliament may give to the two Houses of Parliament powers, for example, in relation to the control of subordinate legislation, or the recently created power of the House of Commons to cause an anticipated general election.

(f) Parliament’s non-legislative and non-statutory powers are essentially political – enforcing the constitutional conventions of ministerial accountability and collective cabinet responsibility, and acting as Winston Churchill’s ‘grand forum of the nation’.

(g) A notification to the European Council of an intention to withdraw is a political act, subject to the constitutional conventions mentioned in (f) above. It does not ‘trigger’ anything. It fulfils a UK treaty obligation, enabling the European Council to begin the formal process of drawing up negotiating guidelines.

6. Negotiation of a withdrawal agreement

The negotiation of a possible withdrawal agreement has already begun.  As noted above, there are three phases of negotiation – (1) a political process within the UK to establish the general lines of the UK’s future relationship with the EU; (2) a preliminary negotiation with the European Council establishing a framework for the actual negotiation, enabling it to establish the guidelines for the formal negotiation of the agreement; (3) the negotiation of the withdrawal agreement. Steps (1) and (2) have already begun. Whether they should be continued into step (3) is a political decision, subject to the constitutional conventions mentioned in 5(f) above.

Four further points should be noted.

(a) The negotiation would be immeasurably more complicated than the accession negotiations of 1971-72. The law and structures and systems of the EU are immeasurably more extensive and complex than those of the European Communities in those days. The EU itself also now has a very large volume of treaty relations, multilateral and bilateral. There would have to be parallel negotiations to restructure the UK’s relationship to those treaties.

(b) The constitutional role of public opinion has changed dramatically in the meantime, with relentless exposure and discussion of all public affairs, in media of communication that are 24-hour and irresistible. It would not be possible to conduct the negotiations in the relatively secretive way in which the accession terms were negotiated. Even if Whitehall were determined to be as secretive as possible, leaks of negotiating positions from external sources could not be prevented.

(c) The Houses of Parliament would surely want to track the negotiations in existing committees or in newly established committees. And the devolved governments in the UK would surely want to be involved in some continuing way.

(d) International negotiators are capable of overcoming, in forms of words, any negotiating challenge. But four issues of a constitutional character seem particularly daunting. (1) In what way would the UK be involved in decisions taken by the EU institutions that seriously affect the UK? (2) To what extent would EU law remain applicable in the UK, even if its supremacy over UK law were removed? (3) Would the European Court of Justice have jurisdiction over the withdrawal agreement, given that the agreement would bind the EU institutions and the remaining member states, and given that the agreement would be a treaty between the UK and the EU governed by international law? (4) Would the International Court of Justice have jurisdiction over the agreement?

7. Implementation of a withdrawal agreement

There would be an UnEuropean Communities Bill to replace the European Communities Act of 1972. Like section 2 of that Act, its drafting would inevitably echo, by similarity rather by difference on this occasion, the terms of Henry VIII’s Act of Supremacy of 1534 which excluded the jurisdiction of the Church of Rome from Britain. These things are remarkable examples of the legislative supremacy of Parliament, in a country which does not have a written constitution.

Three points should be noted.

(a) The disentangling of UK law from EU law would be an immense task, since EU law affects almost every aspect of UK law and government and administration. Again, it would be a much more difficult task than introducing European law at the time of UK accession.

(b) The removal of EU law would alter an incalculable number of existing rights and obligations of natural and legal persons in the UK, and settled legal situations based on those rights and obligations. There would be no end to the cascade of legal consequences and of potential litigation.

(c) The legislation would have to be ready to enter into effect on or before the date of UK ratification of the withdrawal agreement or, at the very latest, on or before the date of the agreement’s entry into force.

8. Ratification of the withdrawal agreement and entry into force

In signing and ratifying treaties, the executive branch of government exercises a prerogative power relating to the conduct of the UK’s international relations. Unlike the position in most other countries, parliamentary assent is not required, beyond the passing of the implementing legislation.

On the EU side, the withdrawal agreement would be concluded by the European Council, acting by a qualified majority, after obtaining the consent of the European Parliament. A qualified majority is 55% of the member states, representing at least 65% of the population of the EU (excluding, on this occasion, the UK as a member state and its population).

Three points should be noted.

(a) Implementation of the agreement in other member states would be as difficult, if not more difficult, than in the UK, especially in those countries where constitutional amendments would be required, or where a referendum would be required.

(b) Entry into force of the agreement would presumably depend on ratification by all the other member states. It is possible for a treaty to enter into force with a lesser number of ratifications, perhaps on a provisional or partial basis.  It is difficult to see how that would be possible on this occasion.

(c) Difficulties in securing ratification in particular countries might lead to a need for partial renegotiation and amendment of the withdrawal agreement. A striking precedent is the renegotiation and amendment of part of the UN Law of the Sea Convention, designed to remove objections (so far unsuccessfully) to ratification of the Convention by the United States of America.

Conclusion. The withdrawal of the UK from the EU is a legal enterprise of unprecedented complexity, involving the exercise of legal powers under three legal systems.  The Rule of Law, as a fundamental principle of liberal democracy, means that the legality of the exercise of those powers may be determined by the laws and the courts of those legal systems.

Philip Allott is Professor Emeritus of International Public Law at Cambridge University and a Fellow of Trinity College Cambridge. His Eutopia. New Philosophy and New Law for a Troubled World was published in July 2016.

(Suggested citation: P. Allott, ‘Fundamental Legal Aspects of UK Withdrawal from the EU: Eight Stages on the Way to a New Relationship’, U.K. Const. L. Blog (9th Nov 2016) (available at

16 comments on “Philip Allott: Fundamental Legal Aspects of UK Withdrawal from the EU: Eight Stages on the Way to a New Relationship

  1. truthaholics
    November 9, 2016

    Reblogged this on | truthaholics and commented:
    “Conclusion. The withdrawal of the UK from the EU is a legal enterprise of unprecedented complexity, involving the exercise of legal powers under three legal systems. The Rule of Law, as a fundamental principle of liberal democracy, means that the legality of the exercise of those powers may be determined by the laws and the courts of those legal systems.”

  2. dbfamilylaw
    November 9, 2016

    Reblogged this on dbfamilylaw.

  3. daveyone1
    November 9, 2016
  4. Sebastian Kornhauser
    November 10, 2016

    I am grateful for the elegant precision of Professor Allott’s clarification in (Fundamental Legal Aspects of UK Withdrawal from the EU: Eight Stages on the Way to a New Relationship’, U.K. Const. L. Blog (9th Nov 2016)). He has cleared a path through a jungle of constitutional chaos by providing a concise, ease to follow explanation of the legal position ‘as it is’ and ‘as it might be’ to what is otherwise a profusely complicated and technical augury of things to come. The definition of ‘may’ as a power and ‘shall’ as a legal obligation will become critical in the future interpretation of article 50. I would like to add that I fundamentally agree with what Professor Allott has said.

  5. alice bouilliez
    November 10, 2016

    One thing forgotten here is the concept of individual fundemental human birthrights that expressly need the wish of each individual to be heard.Only those who have taken an oath of alliegance to a particular government can have their fundemental rights affected by a coleigiate descision.

  6. Mike Fearon
    November 12, 2016

    This useful contribution to the debate highlights, but doesn’t make a lot of, something which should perhaps be the most significant point for the Supreme Court to consider.

    Is a decision by the Executive to withdraw from the EU and relevant treaties in accordance with the constitutional requirements of the U.K., in the light of the Referendum and parliamentary authorisation thereof?

    The current government, following the assumptions previously made by the previous Prime Minister, clearly believe that the decision has already been taken. Unless the Court finds that decision “unconstitutional” and outwith the powers of the executive, either the Executive or Parliament is bound by existing treaty obligations to give notice of it. If the extant decision itself is “constitutional” there seems to be no value in Parliamentary authorisation of notification, and no requirement for an Act of Parliament.

    It is hugely important that the Court is presented with arguments which demonstrate the logical and sequential nature of the withdrawal process, as so ably outlined by Prifessor Allott. These can be summarised as:

    1. Decide to withdraw
    2. Give notice as required
    3. Commence the established process of negotiating the terms of withdrawal.

    The third task cannot commence before the first two. Debate about the terms of withdrawal is either part of the first step, or a sterile activity between steps 1 and 2. The court, Pariament and the litigants should all understand this clearly.

    The litigants themselves appear to accept that the decision has been made and should not be revisited. This statement on their behalf begs the question of why the case has not been withdrawn before it arrived at the High Court. It firmly contraindicates any contribution to the costs of the whole process by the taxpayer. It may also invite some degree of censure by the court: unless the litigants are in fact asking for the withdrawal decision itself to be revisited, the action is frivolous and wasteful in the extreme.

    • Philip Allott
      November 14, 2016

      Thank you. Perhaps useful to add this about para 4(b) of my paper: the crucial difference between a ‘notification of intention to withdraw’ and a ‘notification of withdrawal’. Treaties often provide for a unilateral right of withdrawal, which takes effect automatically on a certain date – for example, Article 58, ECHR; Article 13, NATO Treaty). In the case of the EU, it is not a unilateral right of withdrawal, but an agreed or conditional withdrawal – conditional on the agreement of all the parties, and taking effect on the entry into force of the withdrawal agreement. The ‘notification of intention to withdraw’ is designed to enable the EU to start its side of the formal process.

      • Mike Fearon
        November 15, 2016

        Yes, I agree that is useful, thank you. The (in my view, and I think yours also, highly unlikely) fallback position is relevant though, in that withdrawal can happen without agreement. Even that, however in a sense is multilateral, as there is almost an agreement by default to allow that to happen.

    • Rodger Harris
      November 28, 2016

      I agree, there is no manner in which a lawyer can deduce the formal decision at law, as opposed to political buffoonery from anywhere in these proceedings, as the tectonic constitution which we enjoy does not require one.
      The Government could make a statement in the House of Commons that the decision has been taken and the prerogative exercised, which would provide a formal decision upon which the EU can fasten its constitutional jaws, as much as a Parliamentary vote would.
      However, it does not lie in the mouth of a German Finance Minister to tell us what our constitutional law says, by sole inferred reference to his own, totally misrepresenting the position.
      With reference to my other posting, forgive me, this is what Schaüble had the gall and if I may say so, pig ignorance, to to say:
      “That won’t work; it would require the country to abide by the rules of a club from which it currently wants to withdraw. If the majority in Britain opts for Brexit, that would be a decision against the single market. In is in. Out is out. One has to respect the sovereignty of the British people.”
      Without of course, respecting any Constitutional process involved.
      Is he attempting to oust us from the EEA of which we are a Member without our actually withdrawing?

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  8. Carol Harlow
    November 19, 2016

    The one point left out of your admirably clear explanation is what happens if ratification cannot be secured? presumable Article 50(3) takes effect and we are ‘out’ without any agreed terms. But where does that leave us? I assume a state cannot be forced to remain as a Treaty member – but anything is possible in international law!

  9. Sebastian Kornhauser
    November 22, 2016

    The commonality between Article 58 of the European Convention on Human Rights (Rome, 1950) and Article 13 of the North Atlantic Treaty (Washington D.C., 1949) concerns the theme of “Denunciation” and the mechanism upon which a “Notice of Denunciation” can be given. Brexit is broader than that, (that is to say, more wide ranging than mere Treaty denunciation formalities). It is a phenomenon that is oppositio oppositorum to irredentism and closer to Article 4 of Chapter II of the Constitution of the Union of Soviet Socialist Republics (USSR) of January 1924 “Each one of the Member Republics retains the right to freely withdraw from the Union” under the heading: “Sovereign Rights of the Member Republics”. It would necessarily follow that Brexit is synonymous with a comprehensive right of dissociation (rather than denunciation) because it inaugurates for the awakening of a national sovereign right for the wholesale repudiation of a supranational legal order (the EU) and the exercise of a refusal at national level to what is perceived as supranational subordination.

  10. Rodger Harris
    November 28, 2016

    I was hoping that ghere woud be an aditional article on the issue of the current UK membership as a contracingparty wit the EEA.
    That Treaty is base upon a dichotomy between teh Efta States, saving Switzrrland and the EU Member States.
    The’r is two pîllar process for implementing the decisions etc that this Treaty renders possible. I stress that teh dichotomy inhernet enbales EFTA to function alondgdwide an integrated internal matket, without dsurendering the Free Trade aspects whichappear to have been one reason for the Brexit vote.
    The United Kingdom can file a withdrawal notice under article 127 of the EEA Treaty. however I believe that, as there was no referendum on this point, the message being withdrawal from the EU, the Government’s reliance upon a referendal advisory/semi-mandate is simply not applicable to an decision as to remaining within or going without the EEA. The Government therefore retains its prerogative for terminating or not terminating the EEA reaty, without the need for Parliamentary authority.
    At the risk of admittedly crasse generalisation, the EFTA/EEA integration of EU legislation is well documented on the EEA Website. It would therefore perhaps provide a legislative safety net or even a trampoline for a good many of the issues raised by dare I say Brextrication in the article, which I find sensible.
    I take up the excellent point raised by Sebastian Kornhauser, as that is exactly what is going to happen.
    The question is how is the process of Brextrication going to be achieved?
    The next question, which may be part of that, is to what extent can continued membership, or not, of the EEA soften the exit, as all EU States whichhave joined the EU fomr the EEA have, simpy for differngtials in fundamntal econmic policies, surrendered their seat at that table.
    Economically, reverting to the old EFTA EEA seat would be logical as it would reflect the change in economic/legal environment. It could be used as a transitional measure, whilst the UK manages its extraction within the EEA framework.
    It would be difficult for the Brexiteers manfully lifting the Norwegian (EFTA Member) standard, or whatever form that takes since 1066, to cry foul, as that is one of their “solutions”. it would also enable the UK to “substitute” for Iceland which is seeking to leave the EEA for the EU.
    Is a two gear derailleur Europe gradually taking form?
    Will this in fact enable States to move in and out as political and economic circumstances dictate?
    Monnet might actually not be turning in his grave, as he was a subtle old snake….
    That may be for the next generation of lawyers to manage.
    Brextrication needs tooling not drafting lunacy such as Carswell’s three line hatchet job.

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