Does Brexit Require Legislation?

Assuming the UK’s exit route from the EU is Art 50 of the Treaty on European Union, can this be invoked without resort to an Act of Parliament? This has implications among other things for whether there is a Scottish power to block Brexit.  Lord Lester of Herne Hill asserts in the Times that an Act would be required, and there is a detailed argument by Nicholas Barber, Tom Hickman and Jeff King that agrees. David Cameron took the opposite position in his resignation speech. I think Cameron is clearly correct, and will here explain why.


International Law and Domestic Law

The primary source of international law today is agreements between states. International law is binding upon states, not the individuals and entities within states who are not parties to these agreements. States themselves are like corporations: they are legal constructs with no physical existence (despite all the trappings of flags and so on). They can only act through real world agents. Which agents have the authority to bind states?


The answer is the governments of those states. If the UK government enters into a treaty with Ruritania, that binds the UK. An Act of Parliament is neither necessary nor sufficient as a matter of international law to bind the UK. Once upon a time, these agreements would have been entered into by monarchs. Today they are entered into by the UK government, usually acting through its Prime Minister. This does not enable the UK government to change UK domestic law. If UK domestic law says “X” and the UK government enters into treaty obligations that say “not-X” UK domestic law remains “X”. The two bodies of law, binding on different entities, will say different things


Such agreements do not become incorporated into the UK’s domestic law without more ado.The European Union is the product of several such international agreements. Just as the Human Rights Act incorporates the European Convention on Human Rights into UK domestic law, so the European Communities Act 1972 incorporates the “rights powers, liabilities, obligations and restrictions from time to time created by or under the [EU] Treaties” into UK domestic law. It is through this route that the laws of the European Union are binding on us within UK domestic law.


Is Repeal of the European Communities Act required?

One route for removal of EU law from UK domestic law would be to simply repeal the European Communities Act. This however would place the UK in breach of its treaty obligations under international law, and is, as a result, an inconceivable option.


However EU law provides its own internal mechanism for change. It is for this reason that fresh legislation is not required each time a new regulation or directive is set down. The European Communities Act incorporates such “rights, powers etc” as from time to time apply to the UK under the Treaties. If under those Treaties no “rights, powers etc” apply, no fresh Act is required to effect such change.


Article 50 of the Treaty on European Union provides

  1. Any Member State may decide to withdraw from the Union in accordance with its own constitutional requirements.
  1. 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. That agreement shall be negotiated in accordance with Article 218(3) of the Treaty on the Functioning of the European Union. It shall be concluded on behalf of the Union by the Council, acting by a qualified majority, after obtaining the consent of the European Parliament.
  1. 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.


If this procedure is followed, then there is simply nothing left for section 2 of the European Communities Act to bite upon. The UK is not bound by EU law, and there is nothing left for the statute to incorporate into our domestic legal order.


It is for the government, not Parliament, to act for the UK both in entering into and in exercising powers under international law. Nothing in the European Communities Act either expressly or implicitly alters that. That is what our law says with regard to Art 50(1). Once the Article 50 procedure has been followed, there would be no further need to repeal the European Communities Act. Domestic law incorporation falls with the international obligations.


13 thoughts on “Does Brexit Require Legislation?

  1. However, it does seem that any new arrangement will require legislation, no?

    And perhaps as importantly, since there are arguments on both sides, it’s hard to see how the government might act without a legal challenge.

    Finally, surely parliament can legislate to prevent invoking of Art. 50 if there is a majority for doing so?

  2. ‘If under those Treaties no “rights, powers etc” apply, no fresh Act is required to effect such change.’

    Should that be ‘…new “rights,powers etc”…’?

  3. The implication of your argument seems to be that a prerogative act may deprive private parties of rights they currently enjoy (e.g. passengers who are denied boarding by an airline).

    • On its own? No. What enables this removal is the ECA. Under the ECA we only have such rights under EU law as EU law stipulates. If EU law stipulates ‘none’ that is how many rights we have under EU law..

  4. “One route for removal of EU law from UK domestic law would be to simply repeal the European Communities Act. This however would place the UK in breach of its treaty obligations under international law, and is, as a result, an inconceivable option.”
    Surely not if Britain repealed the European Communities Act with the actual date to be decided in the future and until then still complied with those treaty obligations. It would get round the two year negotiation limit and could go on for longer – if the EU was willing!

  5. “I’ve changed my mind. The decision to leave is neither for parliament nor a prerogative. It’s a statutory power under s2(2)(a) of 1972 Act.” (Adam Tucker on twitter today)

    Does that change your mind at all? Seems to be that a minister can exercise the power, but that s/he does that by stat instrument (sched 2) – so the net effect is that parliamentary approval is needed.

    (I am *not* a constitutional lawyer btw.)

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