The judges did not hand down a finely balanced, on-the-one-hand-on-the-other-hand ruling. They delivered a comprehensive, closely argued denunciation of the government’s case that it could begin the process of leaving the EU without consulting the legislature. Drawing on precedents going back four hundred years, the judges upheld the right of the UK Parliament to decide on people’s rights and not to have those rights removed by executive fiat. The judges noted that the government itself had said that Brexit would be irreversible once it triggered Article 50 of the EU Treaty—and that, therefore, this act would set Britain on an inevitable course toward stripping away those rights that depend on UK membership of the EU.

Hence, the parliament needed to have its finger on the trigger, just as over the past forty-four years it has needed to pass the laws that created and amended Britain’s relationship with the EU. By finding against the government, the High Court was protecting a number of rights. More accurate headlines would have been “Friends of the People” or “The Judges Versus a High-Handed Executive.”

To which Brexit supporters would surely respond: the effect of the judges’ ruling is not to thwart an arrogant government but to thwart the will of the people, as expressed in the referendum held on June 23.

The judges demolished this argument with impressive brutality. They reminded observers that the act to hold the referendum “was passed against a background including a clear briefing to parliaments explaining that the referendum would have advisory effect only.” This, they said, was in line with the “basic constitutional principles of parliamentary sovereignty.” A referendum could only be advisory “unless very clear language to the contrary is used in the referendum legislation in question.” That led to the pungent payoff: “No such language is used in the 2015 Referendum Act.” It follows that this year’s referendum could not be the last word on whether the UK left the EU.

This section of the ruling goes to the heart of the matter yet was somehow overlooked by most of the UK journalists reporting the verdict.

That said, the High Court may not have the last legal word on the matter. The government has said it will appeal to the UK Supreme Court. That tribunal might come to a different view and rule that the government has the right, using the centuries-old royal prerogative, to invoke Article 50. Given the emphatic nature of the High Court’s ruling, this looks unlikely—but it’s possible.

One way forward has been offered by Lord Kerr, a former senior UK ambassador to the EU and secretary general of the 2001 European Convention, which drafted what became the Lisbon Treaty. He is strongly pro-EU and is currently advising Scotland’s government on how to protect its position, given that a clear majority of Scots oppose Brexit.

In a BBC interview the day before the High Court ruling, he said that triggering Article 50 would not make Brexit irrevocable: “You can change your mind while the process is going on. During that period, if a country were to decide actually we don’t want to leave after all, everybody would be very cross about it being a waste of time. They might try to extract a political price but legally they couldn’t insist that you leave.”

It’s just possible that the Supreme Court will agree with Lord Kerr. It would then follow that triggering Article 50 would not lead to the inevitable loss of any rights, because the parliament would have a subsequent right to block Brexit once the detailed terms of withdrawal were known. That argument would gain force if a number of senior EU figures—German Chancellor Angela Merkel? European Council President Donald Tusk? European Commission President Jean-Claude Juncker?—agreed that the UK could change its mind before Brexit takes effect.

The possibility that the UK will trigger Article 50 and then decide it doesn’t want to leave the EU after all looks feasible, though difficult. For the moment, however, May and her ministers face an uncertain future.

On the one hand, if the Supreme Court upholds the High Court’s ruling, then the UK Parliament will have to pass a new law to tell the EU that it wants to start the two-year countdown to Brexit outlined in Article 50. It won’t be known for some months how long that will take, or whether the bill will be passed in the form ministers want.

On the other hand, if the Supreme Court reverses the High Court’s decision, it is likely to do so because it rules that triggering Article 50 leaves open the possibility that Britain might stay in the EU. In that case, the parliament will be able to look at the detailed terms and decide, perhaps as late as March 2019, whether Brexit would be good or bad for Britain.

Either way, Britain is in for a far bumpier ride than seemed likely just a few days ago.

 

Peter Kellner is a journalist, political commentator, and former president of YouGov.