Almost everyone assumes that once the UK’s Article 50 request is made, that’s it. We’re out and there is no going back.

But the European Union Committee of the House of Lords asked for legal advice on the precise question of whether the UK can change its mind.

They invited two expert witnesses to address the question.

Sir David Edward, a former Judge of the Court of Justice of the European Union, told them: “It is absolutely clear that you cannot be forced to go through with it if you do not want to: for example, if there is a change of Government.”

The other witness, Professor Derrick Wyatt QC, supported this view, saying:

“There is nothing in the wording to say that you cannot. It is in accord with the general aims of the Treaties that people stay in rather than rush out of the exit door. There is also the specific provision in Article 50 to the effect that, if a State withdraws, it has to apply to rejoin de novo. That only applies once you have left. If you could not change your mind after a year of thinking about it, but before you had withdrawn, you would then have to wait another year, withdraw and then apply to join again. That just does not make sense. Analysis of the text suggests that you are entitled to change your mind.”