The devil is in Brexit's detail

The anxiety and anticipation surrounding the UK’s exit from the European Union have (again) hit a fever pitch this week. Yet the focus of such external excitement has been the decidedly calm interior of the Supreme Court.

 The most senior judges in the land have been hearing an appeal from the government against the recent High Court ruling that parliament must be consulted before the exit process can be triggered.

The case centres on a technical point of UK constitutional law. The government argues that it can use a power called “prerogative” to withdraw the country from an international treaty, such as that which underpins the EU.

The original applicants, led by investment manager Gina Miller, maintain that invoking the much-discussed Article 50 would lead to British citizens losing certain rights, rights, they argue, which may only be removed by parliament.

The appeal was opened on Monday by Jeremy Wright QC MP, the Attorney-General for England and Wales. Northern Ireland’s own Attorney-General, John Larkin QC, appeared before the Court on Tuesday, having made reference to this higher authority on two further, home-grown Brexit cases.

Mr Larkin assured the Justices that there is nothing in the Good Friday Agreement, nor the Northern Ireland Act 1998, to preclude the government from using its prerogative to activate Article 50. This was not necessarily what those who had originally brought the cases to Belfast’s High Court – including high-profile local politicians – wanted to hear.

Meanwhile, a different but connected drama played out in the House of Commons, where Labour tabled a motion calling on the Prime Minister to publish her exit strategy before commencing the exit procedure. After days of consideration, the government – which has consistently said it would be a mistake to “show its hand” prior to negotiations with the EU – finally acceded to the demand, but only after amending the motion in a way that commits Labour to the cabinet’s timetable.

However, doubts have been cast upon this proposed schedule by the EU’s chief negotiator, Michel Barnier, who advised the UK on Tuesday that the widely-reported two-year gap between the triggering of Article 50 and the country’s formal withdrawal would need to include time for the bloc to define its position at the start, and to ratify any final decision at the end.

“All in all,” Mr Barnier said, “there will be less than 18 months to negotiate.”

Senior government figures were quick to respond that this still provides “ample” time to secure the most favourable deal (whatever that may be), though this new wrinkle does seem to have caught many off guard.

The myriad working groups and joint committees set up across the UK and its devolved administrations have plenty to do if Theresa May is to publicise her negotiating position before the stated Article-50 deadline – the end of March 2017.

A decision by the Supreme Court is not expected until the new year, but this narrowing window means there will be little time to rest over the festive season.