What is sufficient to constitute an Article 50 decision to leave the EU?

This blog post is by senior lecturer Scott Styles.

The UK stands on edge of the momentous decision to leave the EU. It is therefore vital that the true meaning of Article 50 is understood. In particular it is my contention that this cannot be triggered by the decision of the PM or cabinet but only by Act of Parliament.

Article 50 begins by noting:

 Any Member State may decide to withdraw from the Union in accordance with its own constitutional requirements.

There are two essential elements here. Firstly, only the State which wishes to leave may make such a decision. Secondly, authority to make such a decision must be “in accordance with its own constitutional requirements.” So this in turn leads us to consider the requirements of the British Constitution. (Article 50 then goes on to say “A Member State which decides to withdraw shall notify the European Council of its intention.” The issue of notification is a matter not considered in detail here.)

In Britain it is Parliament which is sovereign, not the Prime Minister or even the whole Cabinet. The UK entered the EU by means of the European Communities Act 1972. The repeal of an Act of Parliament may only be done by a subsequent Act of Parliament to that effect. As the effect of an Article 50 notification is to trigger a two year timeline at the end of which that even UK would automatically cease to be an EU Member State that would be to nullify the effect of the 1972 Act as a matter of EU law. But as a matter of British law a statute may only be repealed by another statute. It therefore follows as a matter of British law that to have sufficient authority a Prime Minister would need that authority of an Act of Parliament to that effect giving him the authority to make an Article 50 notification and prospectively repealing the 1972 Act with effect from two years of making the notification.

To be clear, I do not think the authority of the House of Commons alone would suffice. What is needed is a statute passed by both Houses of Parliament (Lords and Commons) plus subsequent Royal Assent. There is of course the not insignificant issue of the pro Leave decision in the referendum of 23 June, but whilst that is politically very significant it is not legally enough. To comply with the EU legal requirement of a request “in accordance with its own constitutional requirements” a Prime Minster needs to get an Act through both Houses. As both Commons and Lords contain large Remain majorities this may prove challenging for any Prime Minster to obtain.

There is no doubt that a refusal by Parliament to give effect to the decision of a referendum would cause huge public outcry, even a constitutional crisis, but that crisis would be political not legal. There is already some evident of “buyer’s remorse” and that many Leave voters regret their decision or that many who abstained regret abstaining. There are two possible ways to square the political circle of a Remain Parliament defying the “will of the people” expressed in the recent referendum.

The first, and easiest, would be for Parliament to pass an Act authorising an Article 50 notification and repeal of the 1972 Act but to make the coming into effect of that Act conditional on it being approved by a post-legislative referendum.  There is a strong precedent for such a provision in the Scotland Act 1978. Indeed some might even go so far as to want to a 40% of the electorate rule as well as was found in the 1978 Act, although I personally think that would be going to far.

The second way to establish if it really is the “settled will of the British people” to leave the EU would be to hold a General Election (subject to the operation of the Fixed-Term Parliaments Act 2011) on the express issue of EU membership with every candidate declaring where they stand on the issue of EU membership. This might even result in candidates standing as “Labour/Conservative/LibDem Leave/Remain” candidates. If a pro Leave majority was returned then obviously such a Commons would happily pass an “Article 50 Act” and the Lords would be obliged to defer to the Commons on application of that Salisbury Principles.

There is also the argument that the consent of the devolved assemblies is needed, but this is a constitutional novelty. (This argument has not attracted the unflinching support of constitutional lawyers, or indeed a prominent Scottish National Party politician.) The strength of the argument I am advancing is that it rests on the classical Diceyan understanding of the British Constitution.

Scott describes himself as “a mere private lawyer”, but he hopes this blog post might add something to the emerging debate around Article 50. Further analysis of Article 50, and Parliament’s role in relation to it, can be found at the UKCLA blog and by David Allen Green.

Editor’s note: the initial title of this blog was “What is sufficient to constitute an Article 50 notification to leave the EU?” It was edited on 28 June 2016 to change “notification” to “decision”.