In a major setback for British Prime Minister Boris Johnson, Britain's Supreme Court on Tuesday ruled in a historic verdict that his decision to suspend Parliament in the run-up to Brexit was "unlawful".
Commenting on the ruling, Johnson said his government would respect even though he "strongly disagrees" with it.
Johnson suspended, or prorogued, British parliament for five weeks earlier this month, saying it was to allow for a Queen's Speech to outline policies of his new government.
However, Opposition MPs and many members of his own Conservative Party had accused him of trying to escape parliamentary scrutiny during a crunch phase ahead of the October 31 Brexit deadline.
Indian-origin anti-Brexit campaigner Gina Miller had challenged his decision in the UK High Court, which had referred it to the highest court of the country.
"The effect on the fundamentals of our democracy was extreme," Supreme Court President Lady Brenda Hale said, as she handed down the verdict.
"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," she said.
She said the unanimous decision of the 11 justices meant that Parliament had not been prorogued - the decision was null and of no effect -- and it was for the Speakers of the Commons and Lords to decide what to do next.
The ruling marks a major setback for Johnson, who is currently in the US for the United Nations General Assembly session. He had insisted that courts should not intervene in such political matters.
"I don't think this was the right decision. The prerogative of prorogation has been used for centuries without this kind of challenge," said Johnson, as he branded Tuesday's ruling "unusual”.
"There are a lot of people who basically want to stop this country from coming out of the EU and we have a Parliament that is unable to be prorogued and doesn't want to have an election. I think it is time we took things forward," he said.
Admitting that getting a Brexit deal was "not made much easier with these sort of things in Parliament or the courts", he insisted the UK would still leave on October 31 - a pledge he had entered Downing Street with.
Miller had made history a few years ago by forcing Johnson's predecessor Theresa May to seek Parliament's approval before invoking Article 50 which set the clock ticking on Britain's exit from the European Union (EU) in March 2017.
In reference to her latest legal win, she said: "Today is not a win for any individual or cause. It is a win for Parliamentary sovereignty, the separation of powers and independence of our British courts.
"Crucially, today's ruling confirms that we are a nation governed by the rule of law – laws that everyone, even the prime minister, are subject to."
She stressed that the historic judgment meant parliament is open and was never prorogued.
House of Commons Speaker John Bercow welcomed the ruling and said Parliament "must convene without delay". He later announced that "in light of the explicit judgement", he had "instructed the Commons authorities to prepare for the resumption of business" from 11:30 am on Wednesday.
Johnson being found to have acted unlawfully and stopped Parliament from doing its job without any legal justification marks an extraordinary legal intervention, which is expected to have a far-reaching impact on British politics.
The legal question the apex court judges had to resolve was whether the prime minister's decision – exploiting residual, royal prerogative powers – was "justiciable" and could consequently be subjected to scrutiny by the courts.
While the England high court to intervene, a Scottish appeal court had concluded that judges did have legal authority to act. In a unanimous verdict, the court ruled that Johnson's decision to prorogue Parliament can be examined by judges, overturning the ruling of the High Court in London.
"Unless there is some parliamentary rule of which we are unaware, they can take immediate steps to enable each house to meet as soon as possible. It is not clear to us that any step is needed from the prime minister, but if it is, the court is pleased that his counsel have told the court that he will take all necessary steps to comply with the terms of any declaration made by this court," Lady Hale said in her ruling, which declared Johnson's suspension "void and of no effect”.
The court stopped short of declaring that the advice given by Johnson to the Queen was improper. It was a question they did not need to address since they had already found that the effect of the prorogation was itself unlawful.
Opposition Labour Party's Ian Murray, one of the MPs who brought the case in Scotland, described the result as "historic" and an “astonishing rebuke to Boris Johnson for his disgraceful behaviour”. He and Labour leader Jeremy Corbyn instantly called on the prime minister to resign.
"I invite Johnson, in the historic words, to 'consider his position' and become the shortest prime minister there's ever been," he told delegates at the ongoing Labour Party's annual conference in Brighton.
UK government lawyers had told the Supreme Court, a building directly opposite to the Houses of Parliament in Westminster in London, that the justices should not enter into such a politically sensitive area, which was legally “forbidden territory” and constitutionally "an ill-defined minefield that the courts are not properly equipped to deal with".