This extension shows a contempt for precedent

Every day of the Brexit process brings new and startling turns, but Theresa May’s latest gambit moves events into new realms of astonishment.

On Friday, she instructed Sir Tim Barrow, our man in Brussels, to write a letter to the EU which formally agrees to Article 50 being extended to April 12 (at least), without first waiting for Parliament to approve the extension.

The EU (Withdrawal) Act 2018 governs our exit from the EU. It says that “exit day” will be on March 29. After that day, the European Communities Act 1972 – which gives effect to EU treaty obligations in UK domestic law – will be repealed.

But the 2018 Act also allows “exit day” to be changed – by a special piece of legislation called a “statutory instrument” (SI) – so long as it is approved by a vote in each House.

Those votes are expected this week. But the Government is claiming that because of Sir Tim’s letter, the extension has already happened. All that will happen if the SI is voted down, says the Government, is that the UK’S internal law will be not be changed to match the new exit date, which has been internationally agreed.

So voting down the SI will cause legal chaos because the UK’S internal law will not conform with our international obligations, and won’t actually prevent us from still being an EU member state and bound by the EU treaties for this extra period. The Government is effectively saying to Parliament: “You can’t stop it! If you vote against it, you’ll just cause chaos!”

This is contrary to constitutional convention and practice. Whenever the Government proposes to enter into an international law obligation, it will not finalise that obligation until Parliament has passed the legislation. This convention and practice is just as applicable to a time extension under Article 50, because it affects the rights and obligations of every citizen. They will (among other things) remain EU citizens for a longer period. It also automatically makes the UK liable to pay into the EU budget for the extended period. It is unconstitutional to incur such a financial liability without a vote by the Commons.

And what is the point of Parliament carefully legislating to say that “exit day” can only be changed with an affirmative resolution of each House, if the Government can pre-empt those votes and force Parliament into approving the extension because the alternative is chaos?

So Parliament needs to hold the Government to account for this contemptuous behaviour.

And what is the legal position? In the Gina Miller case, the Government’s prerogative powers could not be used to give notice under Article 50 because that would affect rights and obligations of people in the UK. The Supreme Court held this was contrary to the intention of Parliament as reflected in the 1972 Act.

Similar logic would seem to apply to an extension of Article 50. It seems that Theresa May’s premiership has now reached a reckless and desperate phase in which she is willing to depart from constitutional precedent in order to pre-empt the tiresome necessity of a parliamentary vote. If constitutional proprieties are not sufficient to rein in her conduct, the next step may have to be a legal challenge to the validity of the Sir Tim Barrow letter on similar grounds to the Gina Miller case.

If her deal is not passed this week, it is possible that she will then seek a much longer extension.

It ought to be inconceivable that any Prime Minister could bindingly agree under international law something as serious as an Article 50 extension to the end of the year – or even to the end of 2020 – without Parliament’s approval, but there is every reason to fear that this is what our rogue Prime Minister could do.