The U.K.’s top judges inflicted an unprecedented legal defeat on Prime Minister Boris Johnson, branding his controversial decision to suspend Parliament unlawful and calling on lawmakers to return to Parliament as soon as possible.
The unanimous landmark decision by the 11 judges Tuesday is a boost for MPs seeking to prevent Mr. Johnson from pulling the country out of the European Union by Oct. 31 without a deal. By limiting the prime minister’s power to suspend Parliament in the future, the judges also deprived Mr. Johnson of one of his last weapons to force through Brexit before his self-imposed deadline.
The decision to prorogue Parliament was “unlawful, void and of no effect,” Judge Brenda Hale, president of the Supreme Court, said in delivering the ruling. The decision to “prorogue Parliament was unlawful because it had the effect of frustrating or preventing the ability of Parliament to carry out its constitutional functions without reasonable justification.”
The prime minister’s opponents had argued that the suspension was a sham designed to stymie democratic scrutiny. Mr. Johnson, who is in New York this week trying to negotiate a revised deal with European leaders, now faces the challenge of getting Brexit through Parliament without a majority, full control over the parliamentary timetable or a way to avoid scrutiny from lawmakers.
The pound initially advanced on the court’s decision, but markets quickly settled back as traders assessed the lingering uncertainty.
Speaker of the House of Commons John Bercow called for Parliament to reconvene.
“As the embodiment of our Parliamentary democracy, the House of Commons must convene without delay,” Mr. Bercow said in a statement. “ To this end, I will now consult the party leaders as a matter of urgency.”
The legal challenge to the powers of the prime minister shows how the political infighting over Brexit has strained Britain’s largely unwritten constitution to its limits. It has also pushed the judiciary into the uncomfortable position of having to rule on a question of politics, something Britain’s Supreme Court has largely eschewed.
“This is an extraordinarily strong, and most importantly unanimous judgment,” Ros Kellaway, a partner at the law firm of Eversheds Sutherland. “There is no wiggle room for the government here. Furthermore, the court has dealt immediately with the effect of its judgment on the unlawful prorogation, Parliament can start sitting immediately.”
With the deadline to pass an exit deal currently set for Oct. 31, lawmakers have already passed legislation requiring Mr. Johnson to seek an extension to the negotiations with the EU until the end of January. Some of the litigants in this case have already started proceedings to ensure that extension is requested, even if Mr. Johnson refuses to make it himself.
“I think it shows people that this government is wholly incapable of solving the Brexit crisis,” Anna Soubry, a member of Parliament who quit Mr. Johnson’s Conservative Party earlier this year.
Jeremy Corbyn, head of the opposition Labour Party, and Liberal Democrat leader Jo Swinson called on Mr. Johnson to quit after the ruling.
The Scottish Nationalist Party’s Joanna Cherry said if Mr. Johnson “had a shred of integrity he would jump before he is pushed.”