MPs will return to Westminster on Wednesday after the highest court in the land ruled Boris Johnson’s suspension of Parliament was unlawful.
In a devastating ruling, the 11 Supreme Court justices agreed unanimously that the five-week prorogation in the run-up to Brexit was “void and of no effect”.
Commons Speaker John Bercow announced that he was putting in place arrangements for MPs to sit at 11.30am on Wednesday. The House of Lords will sit from 3pm the same day.
“The citizens of the UK are entitled to expect that Parliament does discharge its core functions, that it is in a position to scrutinise the executive, to hold ministers to account and to legislate if it chooses,” Mr Bercow said.
The ruling is a bitter humiliation for the Prime Minister, who was in New York for the United Nations General Assembly when the verdict was announced.
There was no immediate response from Downing Street as ministers and senior advisers considered their options.
However, opposition leaders said Mr Johnson’s position was untenable after such a comprehensive ruling and called on him to resign.
Jeremy Corbyn told the Labour Party conference in Brighton: “I invite Boris Johnson in the historic words to consider his position and become the shortest-serving Prime Minister there’s ever been.”
His call was echoed by the SNP leader at Westminster Ian Blackford, who declared: “We must be back in Parliament immediately.
“We want to get back to work. On the back of this, Boris Johnson must resign.”
Liberal Democrat leader Jo Swinson said: “The court have found what we all knew all along – Boris Johnson has again proven he is not fit to be Prime Minister.
“This shutdown was an unlawful act designed to stop Parliament doing its job and holding the Government to account.”
Former prime minister Sir John Major – who supported the case brought by businesswoman Gina Miller against the Government – said Mr Johnson should make an “unreserved apology”.
“I hope this ruling from the Supreme Court will deter any future Prime Minister from attempting to shut down Parliament, with the effect of stifling proper scrutiny and debate, when its sitting is so plainly in the national interest,” he said.
“No Prime Minister must ever treat the Monarch or Parliament in this way again.”
Announcing the result, the court’s president Lady Hale said the Government’s advice to the Queen 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”.
She said the prolonged suspension of parliamentary democracy took place in the “quite exceptional circumstances” of the UK’s impending exit from the EU on October 31.
She added: “Parliament, and in particular the House of Commons as the elected representatives of the people, has a right to a voice in how that change comes about.
“The effect upon the fundamentals of our democracy was extreme.”