Boris Johnson has vowed to press on with his plans for Brexit despite a devastating ruling by Britain's highest court that his suspension of Parliament was unlawful.
The British prime minister said he would abide by the finding of the Supreme Court that the five-week prorogation was "void and of no effect" - even though he disagreed with its conclusion.
A government source said Mr Johnson had spoken to the queen "after the verdict" but would not say whether he apologised to her.
The PM also held a telephone call with his full Cabinet lasting for about 30 minutes to update them on the ruling, expressing that he disagrees with the decision but that he respects the independence of the judiciary, an official said.
Following the legal bombshell, Commons Speaker John Bercow announced that MPs would return to Westminster on Wednesday with the House sitting at 11.30am.
The ruling prompted immediate demands from opposition for Mr Johnson to quit amid claims his position had become untenable.
Downing Street insisted there was no question of Mr Johnson - who was in New York for the UN General Assembly when the result was announced - stepping aside.
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A No 10 source said: "The PM will not resign following the judgment."
While the prime minister, who will fly back to the UK overnight, said the return of MPs would go ahead, he made clear his unhappiness with the court's "unusual judgment".
"I strongly disagree with this decision of the Supreme Court," he told reporters.
"I have the utmost respect for our judiciary, I don't think this was the right decision, I think that the prorogation has been used for centuries without this kind of challenge.
"I think the most important thing is we get on and deliver Brexit on October 31, and clearly the claimants in this case are determined to frustrate that and to stop that.
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"I think it would be very unfortunate if Parliament made that objective which the people want more difficult but we will get on."
Commons Leader Jacob Rees-Mogg will set out the business for the week on Wednesday, but the PM will not land from New York until midday - half an hour after the resumption of Parliament - following a delay to his UN speech.
Announcing the result, the court's president Lady Hale said the British government's advice to Queen Elizabeth 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."
Mr Bercow welcomed the court's rejection of the government's claim that the closure of Parliament was "standard practice" to allow for a new Queen's Speech setting out its legislative programme.
"In reaching their conclusion, they have vindicated the right and duty of Parliament to meet at this crucial time to scrutinise the executive and hold ministers to account," he said.
At the Labour Party conference in Brighton, Jeremy Corbyn said the court ruling had shown Mr Johnson's "contempt for democracy" and his "abuse of power".
"I invite Boris Johnson in the historic words to consider his position and become the shortest-serving prime minister there's ever been," he said.
The SNP leader at Westminster Ian Blackford said once it was clear Parliament had blocked a no-deal Brexit, the opposition parties should combine to pass a vote of no confidence.
"We cannot tolerate this man who is behaving in an undemocratic manner, behaving like a dictator," he said.
"He has to be removed from office and the opposition has to come together, the opposition has to do its job."
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."
Mr Johnson, meanwhile, was facing calls to sack the advisers who persuaded him to seek a prorogation, including his controversial chief adviser Dominic Cummings.
Former justice secretary David Gauke, who lost the Tory whip after rebelling over Brexit, said: "I think he needs a change of strategy and I think he needs a change of strategist."
The Supreme Court ruling arose out of separate legal challenges in England and Scotland, in which leading judges reached different conclusions.
While the High Court in London found the prorogation was "purely political" and not a matter for the courts, the Court of Session in Edinburgh ruled it was unlawful because it was for "the improper purpose of stymieing Parliament'".
Attorney General Geoffrey Cox had advised the prime minister that the suspension would be lawful.
An Attorney General's Office spokesman said: "We are disappointed that in the end the Supreme Court took a different view. We respect the judgment of the Supreme Court."
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