Does Parliament need to OK Brexit? Britain's Supreme Court to decide.

Britain's highest judicial body will decide whether the government can trigger the process to separate from the European Union without parliament's approval.

First Look

Britain’s highest judicial body, the Supreme Court of the United Kingdom, began hearing Monday a case concerning a British exit from the European Union, or Brexit. Consideration by the nation’s top judges comes after three High Court judges last month ruled that the government must consult with Parliament before beginning the official process of leaving the EU.

The government appealed that decision, and the ruling sparked fury among some Brexit supporters who felt it was an attempt to overturn the result of June’s referendum, which saw 52 percent of participating voters call for a divorce from the EU. The Daily Mail, an anti-EU newspaper, labelled the High Court judges “enemies of the people.”

Yet the case now sitting before Britain’s top 11 judges is not, at its heart, about Brexit. The Supreme Court will make no ruling on whether Britain should leave the EU, and nor will they consider what kind of a relationship should be pursued with that body. Rather, it is a constitutional question, a matter of the division of power between the legislature and the executive branch – one that some observers say is of historic importance.

“The Supreme Court exists to decide points of law,” said David Neuberger, president of the Supreme Court and Britain’s top judge, in his opening comments. “[W]ider political questions are not the subject of this appeal. This appeal is concerned with legal issues, and as judges, our duty is to consider those issues impartially.”

And what, precisely, are those issues? In essence, the court must decide whether Prime Minister Theresa May and her government can invoke Article 50 of the Lisbon Treaty, which governs the process of any member state leaving the EU, of their own accord, or whether they must first consult the rest of Parliament, Britain’s body of elected lawmakers.

In a reflection of how important this is – less because of Brexit, and more because of the constitutional implications – all eleven judges will be hearing the case, the first time that has happened since the Supreme Court was founded in 2009.

Some would go further, as does Sarah Helm in an opinion piece for The Guardian, where she describes the hearing as “perhaps the most important constitutional case in 140 years.”

“It has a significance far wider than Brexit,” writes Ms. Helm. “Not since 1876, when law lords first sat, have judges been asked to rule so broadly on who in Britain wields power.”

Until recently, Ms. May and her Cabinet had been proceeding under the assumption that Parliament could be left out of the equation, thus allowing them to keep their strategy under wraps. As The Spectator, a right-leaning British magazine, put it, May and the EU have been involved in a “game of bluff,” with the prime minister seeking to extract as much as possible from any future agreement, but fully aware that Europe needs to be seen to “have its pound of British flesh.”

This clandestine approach may now have to be revised, as may May’s proposed timetable of triggering Article 50 – thereby beginning the official two-year process of negotiation with the EU – by March of next year.

While submitting the government’s strategy and the official launch of negotiations to parliamentary approval could, technically, allow Brexit to be entirely derailed, most analysts agree such an outcome is highly improbable. Members of Parliament, as the elected representatives of the British people, would be loathe to act contrary to the democratically expressed will of that electorate, whatever their personal views on Brexit.

Far more likely, MPs would force the government to soften their stance and veer away from the “hard Brexit” that many people suspect Ms. May is seeking.

But whatever the Supreme Court decides – and a ruling is expected in January – even some supporters of Brexit, and of May’s determination to see it through, wonder whether her secrecy is doing more harm than good.

“For understandable reasons, Mrs May is reluctant to show her hand on Brexit yet,” notes a Telegraph editorial. “But the absence of a clear plan from her is creating unnecessary ambiguity about her intentions – a vacuum that is being filled with speculation, hints and mischief-making by friend and foe alike.”

This report includes material from the Associated Press and Reuters.