The Article 50 Litigation – Why the UK Parliament Still Needs to Vote for (or against) Brexit

Edmund Burke, on being elected MP for Bristol, famously told his new constituents that ‘Your representative owes you, not his industry only, but his judgment’. This was his clever way of saying that he was going to make up his own mind about how to vote in the House of Commons, and not feel bound to do whatever the people of Bristol wanted.

The speech, made in 1774, has stood the test of time. It is the classic statement of an MP’s role in a representative democracy. And its sentiments are embodied in constitutional law – MPs have a duty to make up their own minds, even if they were given a clear message by the electorate in a referendum (see Moohan v Lord Advocate at [48]).

A lot of people who do not much like the idea of Brexit are placing a great deal of weight on this. They think that the EU referendum is not the end of the matter, that MPs still have to vote on whether the UK should leave the European Union, and that Parliament is in no way bound by the wishes of the majority as expressed in the referendum result.

This has led to the first piece of post-referendum litigation. But how far is it accurate?

Article 50 and the UK Constitution

The starting point, as most people know by now, is Article 50 of the Treaty on European Union.

Article 50 allows member states to withdraw from the EU. The process it lays out is simple. The member state gives a notice to the European Council that it intends to leave. There is a notice period of two years, designed to allow time for negotiations on the terms of leaving. The period may be extended by agreement, but once it expires EU membership terminates automatically, whether or not the negotiations have reached a successful conclusion.

In other words, an Article 50 notice is not just a notice of intention to leave the EU at some future date after an alternative arrangement has been agreed. It is also a legally-effective instrument which causes leaving to occur. It works a little like a notice to quit a lease – you do not need to give it, but once you do, as soon as the notice period ends, you have to get out of the house.

David Cameron told the House of Commons in February that if the UK voted for Brexit the public would expect an Article 50 notice to be served straight away. But, when it came to it, the only thing he did immediately was to resign, leaving the mechanics of Brexit to his successor. And she has indicated that service of the notice is at least several months away.

This is frustrating to many in Europe, but as a matter of EU law the referendum changed nothing. The UK is entitled to serve the notice when it is ready, or not at all. Article 50 says that the decision to withdraw from the EU is to be taken by a member state ‘in accordance with its own constitutional requirements‘. And whatever the referendum did, it did not satisfy these requirements and trigger an automatic Brexit. A further decision is needed.

But what are the constitutional requirements of the UK, and who can make that decision?

Before the referendum it was widely assumed that the government would have the power to serve the notice. But after the result was announced, in the space allowed by Cameron’s failure to act immediately, this assumption was quickly challenged.

In a highly influential paper published only three days after the referendum result, Barber, Hickman and King argued that the decision was one for Parliament, not the executive.

Academics and legal practitioners promptly weighed in on both sides of this argument – some agreeing that a parliamentary mandate was necessary, others arguing that the government already had the powers it needed and required no further authorisation.

No overall consensus has emerged. But since this is hardly the time for fence-sitting, I and my colleague Kieran Laird published our view on our firm’s website. Our fuller reasoning can be found there (Can Brexit Still be Prevented?) but the headline points are these –

First, the outcome of the EU referendum was not legally binding. Parliament has made other referendums binding, but not this one. That has to be treated as deliberate.

Second, the argument that the executive can act alone assumes that it can rely on the royal prerogative – the residue of ancient rights and powers that traditionally vested in the Crown. Certainly the prerogative includes the conduct of foreign affairs, including the signing of treaties. However, it cannot be used to override the will of Parliament on a subject on which it has already legislated.

Parliament has in fact legislated, under the European Communities Act 1972, for the EU Treaties and everything flowing from them to become part of UK law. This Act assumes and relies on the UK being a continuing party to the Treaties. If an Article 50 notice is served, that will cease to be the case as soon as the notice period expires. The Act might remain on the statute book, but it would be a dead letter. The executive cannot rely on the prerogative so as to undermine and negate statute law in this way.

Third, the 1972 Act is no normal legislation. It is recognised by the Supreme Court as one of a small group of constitutional statutes to which special protection is afforded. This means that the incorporation of the Treaties in domestic law is treated as part of the UK constitution. It follows that the service of an Article 50 notice may be in form an act in the sphere of foreign relations, but in substance would be an amendment to the constitution. There is no prerogative power which authorises a constitutional change by executive action.

Of course there is no precedent which directly addresses the current situation, so there is infinite opportunity for creative legal argument. However, this seems to me much the best position.

It can be tested in this way. Imagine there was no referendum, and everything had carried on just as before. Could David Cameron one day have served an Article 50 notice, triggering a withdrawal from the EU regardless of the will of Parliament or the 1972 Act? Aside from the political implications, would this have been considered a lawful act ‘in accordance with [the UK’s] constitutional requirements‘?

Those who think that Parliament does not need to vote for Brexit either have to assert that he could have done this and it would have been entirely lawful, or say how a referendum which was not legally binding could nonetheless have had the most profound legal effect possible, empowering the use of the royal prerogative to override the effect of legislation enacted by Parliament. Neither argument appears attractive.

The Article 50 Litigation

Attractive or not, the position of the Government Legal Department appears to be that one or other of these statements is true. On 5 July, Oliver Letwin, at that time still a member of the Cabinet, told the House of Commons Foreign Affairs Select Committee that ‘I am advised by the Government lawyers that, in their view, it [the right to serve an an Article 50 notice] clearly is a prerogative power’.

For the government to adopt this position more or less made litigation inevitable. And, since any action will be one of the most important constitutional law cases of the century, there was no shortage of lawyers wanting to be involved.

One well-regarded claimant firm crowdsourced funding for an action. Another, perhaps better known for its defamation practice, claimed to have existing (but unnamed) clients prepared to litigate, and with the aid of some impressive self-publicising invited others to join in.

Both, however, were beaten to the punch by a London hairdresser, Deir Dos Santos. While the other potential claims were still at the fundraising or letter writing stage, Dos Santos and his barrister, Dominic Chambers QC (who is acting pro bono), commenced action on 28 June, just four days after the referendum result.

Dos Santos subsequently brought on board a law firm known for its work on class actions, which might imply that further claimants will be added to his case. Aside from this, not much information about this claim is currently in the public domain. But that is about to change – the case is listed for a permission hearing before the Divisional Court on 19 July, which will be widely publicised.

Since no decision has yet been made to serve an Article 50 notice, the claim is presumably for a declaration that the notice requires parliamentary approval, and an order prohibiting the government from acting without it. If interim relief has been applied for, the hearing is likely also to deal with that application.

There should be no question of the case getting permission. The threshold test is low, and there is no doubt that the claim is (at the very least) arguable. There is also a strong public interest in it being heard. But in circumstances in which there is no real likelihood of an Article 50 notice being served imminently, an interim injunction seems less likely.

The Politics

Dominic Chambers told Reuters that Mr Dos Santos was neutral as to whether the UK left the EU, and simply wanted to see due process followed – ‘My client respects the results of the referendum and he is not in any way doing this to try to prevent Brexit: His sole concern is upholding the rule of law.’

If so, Dos Santos is a laudably disinterested member of the public. Certainly he is right to insist that any decision to serve an Article 50 notice should be made under the proper legal authority. This point ought to commend itself to everyone, including all Leave voters who care about parliamentary sovereignty. However, most people now arguing that Parliament must vote on Brexit appear to have a less neutral agenda.

For instance, on 9 July, over 1,000 barristers wrote a public letter to the Prime Minister and all MPs about the outcome of the referendum. Can 1,000 barristers be wrong about the law? Well, yes, and in 1,000 unique ways. But not on this occasion, I think – the barristers asserted that an Article 50 noticed required the sanction of Parliament. However, having made this point, they moved seamlessly into submissions making it clear that the reason they wished Parliament to vote was so that it would have the opportunity to keep the UK in the EU.

Most of the potential claimants in the other actions currently under consideration will be driven by the same hope.

It is certainly true that when Parliament takes the decision it must take into account all the circumstances prevailing at the time. It must be possible that it delays, or declines to sanction, the service of an Article 50 notice. A vote in Parliament cannot be an exercise in applying a rubber stamp. MPs must exercise their judgment.

However, Remainers may wish not to raise their hopes for the current litigation too high, even if it succeeds. In the first place, no-one should underestimate the political toxicity of an outcome in which the result of the referendum is not honoured. In any case, the extent to which the available possibilities may quickly be narrowed by real world events should not be ignored.

Brexit may still not happen. But even in the space of three weeks the situation has moved on rapidly. With a new Prime Minister who has been unequivocal on the subject, and a new Department for Exiting the European Union under a Secretary of State who is a committed Leaver, momentum could quickly develop to a point at which the prospects of remaining in the EU no longer seem so viable as they did even in the aftermath of the vote.

Theresa May’s statement from her speech in Birmingham bears repeating in full, beyond the oft-quoted soundbite in the second sentence –

‘I couldn’t be clearer. Brexit means Brexit. And we’re going to make a success of it. There will be no attempts to remain inside the EU, no attempts to rejoin it by the back door, and no second referendum. The country voted to leave the European Union, and as Prime Minister I will make sure that we leave the European Union.’

Political promises mean nothing in law (Lucas v Security Service). But these are not words casually uttered by a Tory Prime Minister who is intent on keeping her party together.


Edmund Burke merits a footnote. When he exercised the independent judgment which he had promised his constituents – intriguingly on the subject of free trade with Ireland, one of the issues effectively up for discussion in any EU exit negotiations – he made a virtue of the consequences of acting against their wishes:

‘If, from this conduct, I shall forfeit their suffrages at an ensuing election, it will stand on record an example to future representatives of the Commons of England, that one man at least had dared to resist the desires of his constituents when his judgment assured him they were wrong.’

Noble sentiments. But the people of Bristol also sent their own message to the future. They made Burke’s position so politically untenable that he did not even trouble to submit himself for re-election, and was obliged to fall back, ignominiously, on a pocket borough in the gift of his patron, Lord Rockingham.

Pocket boroughs and patrons are not widely available to MPs in the UK of the 21st Century.