What follows any referendum vote next week for the United Kingdom to leave the EU? From a legal perspective, the immediate consequence is simple: nothing will happen.
The relevant legislation did not provide for the referendum result to have any formal trigger effect. The referendum is advisory rather than mandatory. The 2011 referendum on electoral reform did have an obligation on the government to legislate in the event of a “yes” vote (the vote was “no” so this did not matter). But no such provision was included in the EU referendum legislation.
What happens next in the event of a vote to leave is therefore a matter of politics not law. It will come down to what is politically expedient and practicable. The UK government could seek to ignore such a vote; to explain it away and characterise it in terms that it has no credibility or binding effect (low turnout may be such an excuse). Or they could say it is now a matter for parliament, and then endeavour to win the parliamentary vote. Or ministers could try to re-negotiate another deal and put that to another referendum. There is, after all, a tradition of EU member states repeating referendums on EU-related matters until voters eventually vote the “right” way.
What matters in law is when and whether the government invokes Article 50 of the Lisbon Treaty. This is the significant “red button”. Once the Article 50 process is commenced then Brexit does become a matter of law, and quite an urgent one. It would appear this process is (and is intended to be) irreversible and irrevocable once it starts. But invoking Article 50 is a legally distinct step from the referendum result — it is not an obligation.
Article 50 in full contains the following provisions:
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. 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.
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.
4. For the purposes of paragraphs 2 and 3, the member of the European Council or of the Council representing the withdrawing Member State shall not participate in the discussions of the European Council or Council or in decisions concerning it.
A qualified majority shall be defined in accordance with Article 238(3)(b) of the Treaty on the Functioning of the European Union.
5. If a State which has withdrawn from the Union asks to rejoin, its request shall be subject to the procedure referred to in Article 49.
There are three points of interest here in respect of any withdrawal from the EU by the UK.
First, it is a matter for a member state’s “own constitutional requirements” as to how it decides to withdraw. The manner is not prescribed: so it can be a referendum, or a parliamentary vote, or some other means. In the UK, it would seem that some form of parliamentary approval would be required — perhaps a motion or resolution rather than a statute. The position, however, is not clear and the UK government has so far been coy about being specific.
Second, the crucial act is the notification by the member state under Article 50(2). That is the event which commences the formal process, which is then intended to be effected by negotiation and agreement. There is no (express) provision for a member state to withdraw from the process or revoke the notification. Once the notification is given, the member state and the EU are stuck with it.
And third, there is a hard deadline of two years. This is what gives real force to Article 50. The alternative would be the prospect of a never ending story of rounds of discussions and negotiations. Once notification is given, then the member state is out in two years, unless this period is extended by unanimous agreement. It is possible that such unanimity may be forthcoming – but this would be outside of the power of the member state. Once the button is pushed, the countdown cannot just be switched off by a member state saying it has changed its mind, or by claiming that the Article 50 notification was just a negotiation tactic all along. That will not wash.
This said, what is created by international agreement can be undone by international agreement. Practical politicians in Brussels may come up with some muddling fudge which holds off the two year deadline. Or there could be some new treaty amendment. These conveniences cannot, however, be counted on. The assumption must be that once the Article 50 notification is given, the UK will be out of the EU in two years or less.
What happens between a Leave vote and any Article 50 notification will be driven by politics. The conventional wisdom is that, of course, a vote for Brexit would have to be respected. (This is the same conventional wisdom which told us that, of course, Jeremy Corbyn would not be elected Labour leader and that, of course, Donald Trump would not be the Republican nominee.) To not do so would be “unthinkable” and “political suicide” and so on.
And if there is a parliamentary vote before any Article 50 notification then there is the potential irony of those seeking to defend parliamentary sovereignty demanding that an extra-parliamentary referendum be treated as binding. But it must be right that the final decision is made by parliament, regardless of what the supposed defenders of parliamentary sovereignty say.
One suspects that no great thought went into the practical and legal consequences of a Leave vote because it was expected that the vote would be, of course, for the UK to remain. That may well be the result: nobody knows what will happen next week, and only a fool relies on opinion polls. And referendums do tend to support the status quo (though not always). It could turn out that worrying about what happens if there is a vote for Brexit is misplaced.
What is certain is that if there an Article 50 notification then there will be immense legal work to be done. Over 40 years of law-making — tens of thousands of legal instruments — will have to be unpicked and either placed on some fresh basis or discarded with thought as to the consequences. The UK government has depended since 1972 — indeed it has over-depended — on it being easy to implement law derived from the EU. The task of repeal and replacement will take years to complete, if it is ever completed. Even if the key legislation — especially the European Communities Act 1972 — is repealed there will have to be holding and saving legislation for at least a political generation.
A vote for Brexit will not be determinative of whether the UK will leave the EU. That potential outcome comes down to the political decisions which then follow before the Article 50 notification. The policy of the government (if not of all of its ministers) is to remain in the EU. The UK government may thereby seek to put off the Article 50 notification, regardless of political pressure and conventional wisdom.
There may already be plans in place to slow things down and to put off any substantive decision until after summer. In turn, those supporting Brexit cannot simply celebrate a vote for leave as a job done — for them the real political work begins in getting the government to make the Article 50 notification as soon as possible with no further preconditions.
On the day after a vote for Brexit, the UK will still be a member state of the EU. All the legislation which gives effect to EU law will still be in place. Nothing as a matter of law changes in any way just because of a vote to Leave. What will make all the legal difference is not a decision to leave by UK voters in a non-binding advisory vote, but the decision of the prime minister on making any Article 50 notification.
And what the prime minister will do politically after a referendum vote for Brexit is, at the moment, as unknown as the result of the referendum itself.