Ruth asked:

I’ve been watching the Supreme Court Brexit case and after two days I’m completely confused by all the lawyer-speak. Can you help?

Answer by Geoffrey Klempner

From what we’ve seen so far, and ignoring all the complications and side issues, it’s safe to say that:

According to the ‘Appellant’ — the Secretary of State for Exiting the European Union — the European Union Referendum Act 2015 was intended to ‘hand over’ the decision of whether or not to leave the European Union to the British electorate, requiring no further Parliamentary debate on the question whether to formally commence the process of leaving.

According to the ‘Respondent’ — Miller and Dos Santos who originally won the case against HM Government in the High Court — the force of the Referendum Act could only have been ‘advisory’. A Minister of the Crown does not have the legal right to bring about the repeal of legislation which bears on the rights of British citizens without authorization from Parliament.

What both sides agree on is that the Act didn’t specifically say what should be done in the event of the country voting to leave the EU. This was a banana skin waiting to be stepped on. The Government were confident of winning the Referendum. On a charitable view, they wanted to keep the wording of the Act as simple as possible to avoid having to debate the question of exactly what the process of leaving would involve.

Meanwhile, many members of the public see the question in much simpler, starker terms. Forget about the precise nature of the British Constitution, or the respective roles of Parliament, the Crown and the Judiciary. These issues may be important to resolve but they don’t apply in this case.

Why? Because the European Referendum Act 2015 has a very simple and easy to understand structure, which can be represented in formal logic as a conditional statement:

If A then B.

If the outcome of the Referendum is a vote to Leave (A) then the UK leaves the European Union (B).

What happened? The Government lost the Referendum. The outcome was a vote to Leave.

1. If A then B.

2. A.

3. Therefore, B.

The name of this ancient rule of logic is Modus Ponens.

But how is this supposed to happen? There is a set procedure for leaving — ‘triggering Article 50’ — but the nature of the procedure isn’t important. It’s completely irrelevant. It could just have easily been pressing a red button on the Prime Minister Theresa May’s desk at Number 10 Downing Street. Click, and we’re gone. Any bargaining about future deals can come later. (That wouldn’t be a great idea, but again it isn’t a relevant consideration.)

Then, as both sides are agreed, it would be up to Parliament to pass a ‘Great Repeal Act’ removing EU law from the UK statute books, and clearing up the legislative mess which could possibly take a decade or more.

The excruciatingly simple point is that when Parliament passes an Act which is conditional in nature, it is the job of the executive to implement or not implement the consequence depending on whether the relevant condition is met. It’s got nothing to do with whether or not you think referendums are a good idea, or whether the wishes of the majority ought to be respected, or what should be the limits of the Crown Prerogative.

In passing the 2015 Act, Parliament has already made its decision. It has effectively removed itself from the decision making process in this particular case, regardless of how it may be involved in the future.

Is that the end of the story? Well, no. Because the other side can argue that on this analysis Parliament went wrong in passing this Act with this wording. They effectively surrendered a responsibility that according to the British Constitution they ought not to have surrendered, in the same way — to take an extreme case — as it would be against the British Constitution for Parliament to pass an Act making Theresa May Dictator and permanently dissolving itself.