In a major setback to prime minister Theresa May, the high court in London ruled on Thursday that her government cannot initiate Brexit proceedings without the approval of parliament.
“The most fundamental rule of the UK constitution is that parliament is sovereign,” said Lord Thomas of Cwmgiedd, the chief justice, at the end of three weeks of legal arguments.
He also clarified that the court was ruling on “a pure question of law” and not on the merits of leaving the European Union.
Soon after the verdict was delivered, the government announced plans to appeal.
Mrs May has claimed that the June referendum in favour of Brexit gave her the authority she needed to trigger Article 50, the clause in the Treaty on European Union that initiates the withdrawal of a member state.
She had announced plans to invoke the clause by March next year, a timeline that may now be considerably delayed by further legal and parliamentary procedure.
Markets reacted sharply in the minutes after the court’s ruling, as the British pound spiked and bank stocks rallied.
“The government is disappointed by the court’s judgment,” said Mrs May’s trade minister Liam Fox. “The country voted to leave the European Union in a referendum approved by acts of parliament. The government is determined to respect the result of the referendum.”
The court was ruling in response to petitions filed by two British nationals: Gina Miller, a businesswoman, and Deir dos Santos, a hairdresser. Their arguments were supported by other groups, including People’s Challenge, a crowdfunded movement that raised hundreds of thousands of pounds from supporters to finance its legal fees.
Ms Miller, who was greeted with applause as she emerged from the courts on Thursday, called the verdict “a victory for parliamentary democracy … This case was about process, not politics.”
The petitioners argued that the clause can only be invoked with the approval of parliament.
The Brexit referendum “did not replace the system of parliamentary representative democracy”, Mr dos Santos’s counsel, Dominic Chambers, told the court on the opening day of arguments.
But the government’s lawyers argued that Mrs May is empowered to trigger the clause through the use of the royal prerogative, a centuries-old rule that transfers the powers of a monarch to the UK’s elected leader.
By the same prerogative, the prime minister can also order military action, mint currency, and requisition ships in times of national need.
The limits of the royal prerogative have, however, never been explicitly spelled out. The UK does not have a written constitution, and as a result, court verdicts on constitutional matters always depend on interpretations of uncodified laws and judicial precedent.
That ambiguity was on display in the high court, as both parties tussled over the interpretation of Article 50, which declares that an EU member may leave “in accordance with its own constitutional requirements”.
Jeremy Wright, the attorney general, has held that Mrs May’s actions were constitutional and told the high court that the royal prerogative had always extended to making and breaking international treaties.
“The other parties in this case have sought to say they are defending the sovereignty of parliament,” Mr Wright said. “We say that parliament can retain its sovereignty as much by choosing not to do something as by doing something.”
“It chose not to restrict the way royal prerogative powers work on multiple opportunities,” he added. “The prerogative powers are available to use, we say, to give clear effect to the wishes of the people of the UK that we should begin the process of leaving the EU.”
On appeal, given its importance, the case will bypass the court of appeals and proceed directly to the supreme court.
The top court has already cleared time for hearings by a full 11-judge bench on December 7-8, in case an appeal is filed.
If the supreme court rules against the government as well, that decision may be appealed again at the European court of justice – part of the same EU framework that the UK is trying to leave.
However, it is possible that Mrs May will encounter little opposition to triggering Article 50 in parliament. Although a majority of MPs voted for the UK to remain in the EU, they are unlikely to reverse the results of a referendum altogether.
Last week, Angela Smith, a leader of the Labour Party, told the House of Lords that her colleagues would not stand in the way of Brexit, if Article 50 were to be referred to them.
“We will scrutinise. We will examine,” said Ms Smith. “But my Lords, we will not block. But neither will we be bullied into abdicating our responsibilities. We have to be adult about this.”
ssubramanian@thenational.ae