New world news from Time: U.K. Supreme Court Rules Boris Johnson’s Suspension of Parliament Was Unlawful

The U.K.’s Supreme Court ruled Tuesday that Boris Johnson’s request for the Queen to suspend Parliament was “unlawful, void and of no effect,” in a severe blow for the British Prime Minister.

The ruling means lawmakers could reconvene as soon as tomorrow, allowing them to scrutinize Johnson’s Brexit preparations ahead of the U.K.’s Oct. 31 deadline to leave the European Union.

The opposition Labour Party and the Scottish National Party both responded by calling for Johnson to resign. Parliament’s speaker, John Bercow, said lawmakers must “convene without delay.”

Parliament, the Supreme Court said, “has a right to a voice.” Supreme Court President Brenda Hale continued: “No justification for taking action with such an extreme effect has been put before the court.”

“The Court is bound to conclude, therefore, that the decision to advise Her Majesty 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.”

Before the ruling, the government said it would “abide by” whatever the court decided. But Johnson, who is in New York for the U.N. General Assembly, has not ruled out suspending Parliament for a second time.

The Supreme Court said it was for lawmakers — not the Prime Minister — to decide what to do next.

Justices ruled that the suspension of parliament was not a “purely political” matter, as the government had argued, and therefore could be ruled upon.

The judgment marks one of the most significant rulings in the U.K.’s constitutional history, marking a new precedent for the power the courts have to police squabbles between the government and parliamentarians.

Justices were considering competing judgments handed down by Scottish and English high courts. The English court ruled that Johnson’s advice to the Queen was a political matter, and not one for the courts. But the Scottish court ruled that Johnson’s advice was a matter for the courts — and that it was “motivated by the improper purpose of stymieing Parliamentary scrutiny of the government.”