Boris Johnson was today dealt a historic defeat as the Supreme Court ruled he broke the law to shut down Parliament over Brexit.
The PM faced demands to resign after the UK's highest court ruled unanimously that he acted unlawfully.
The 11 justices said shutting down the Commons for five weeks before the Brexit deadline had an "extreme" effect on democracy.
Declaring the prorogation of Parliament "unlawful, void and of no effect", Supreme Court President Lady Hale declared: "Parliament has not been prorogued."
And she said the Commons and Lords speakers "can take immediate steps to enable each house to meet as soon as possible".
It triggered accusations that the Prime Minister misled the Queen.
Commons Speaker John Bercow triggered urgent talks with party leaders within minutes, declaring: "The House of Commons must convene without delay".
Labour members chanted "Johnson out! Johnson out!" as Jeremy Corbyn gave an unexpected address to the party conference in Brighton following the bombshell result.
Labour's leader warned Boris Johnson could soon become “the shortest-serving Prime Minister there’s ever been”.
He added: “It demonstrates a contempt for democracy and an abuse of power by him.
“I will be in touch immediately to demand that Parliament is recalled so we can question that Prime Minister, demand that he obeys the law that’s been passed by Parliament and recognise our parliament is elected by our people to hold our government to account.”
Deputy Labour leader Tom Watson said: "Boris Johnson should resign."
SNP Westminster leader Ian Blackford added: "Boris Johnson must resign immediately."
Lady Hale said Boris Johnson's prorogation had this effect of "frustrating" Parliament and "no justification" had been given.
She declared: "This was not a normal prorogation in the run up to a Queen's Speech. It prevented parliament carrying out its constitutional role for 5 out of a possible 8 weeks."
Defiant Mr Johnson last night refused to rule out shutting down parliament for a second time ahead of the landmark ruling.
Asked if he could stay if he had misled the monarch, the PM insisted: "No. I think the reasons for wanting a Queen's Speech are extremely good."
Lady Hale said that this prorogation had this effect of "frustrating or preventing the ability of parliament to carry out its constitutional functions without reasonable justifications."
She told the court there had been “no justification” for the decision to prorogue parliament for five weeks.
The Supreme Court spent three days hearing appeals on two conflicting court cases from the Court of Session in Scotland and the High Court in England.
Boris Johnson watched the judgement live from his hotel room in New York where he is attending the United Nations General Assembly.
Speaking ahead of the landmark ruling a defiant Mr Johnson refused to promise to shut down parliament for a second time.
Asked if he could stay in Number 10 if he was found to have misled the monarch, the PM insisted: "No. I think the reasons for wanting a Queen's Speech are extremely good."
The House of Commons said in a statement: "The House service's primary responsibility is to ensure the smooth running of parliamentary business.
"We are considering the implications of the Supreme Court's judgment for Parliament and will provide further information as soon as we can."
Labour ’s shadow Brexit secretary, Keir Starmer, insisted ahead of the ruling that parliament should be recalled “straight away” if the PM has broken the law.
He said: “I will get the first train.”
During a three-day hearing last week eleven justices were asked to determine whether his advice to the Queen to prorogue Parliament, for what opponents describe as an "exceptionally long" period, was unlawful.
Gina Miller, who led the legal challenge against the move to prorogue parliament, said outside the Supreme Court that it was a win for parliamentary sovereignty.
"Today's ruling confirms that we are a nation governed by the rule of law. Rules that everyone even the Prime Minister is not above."
She said: "The ruling today speaks volumes. This Prime Minister must open the doors of Parliament tomorrow.
"MPs must get back and be brave and bold in holding this unscrupulous government to account."
SNP MP Joanna Cherry, who led the case in the Scottish courts, said Boris Johnson's position was "untenable" and called on him to resign.
"This is an absolutely momentous decision. There is nothing to stop us - Members of Parliament - resuming immediately the important job of scrutinising this minority Tory government as we hurtle towards Brexit," she told reporters outside the Supreme Court.
"This is a huge victory for the rule of law and for democracy. As regards Mr Boris Johnson, the highest court in the United Kingdom has unanimously found that his advice given to Her Majesty the Queen was unlawful.
"His position is untenable and he should have the guts for once to do the decent thing and resign."
Brexit Party leader Nigel Farage called for the Prime Minister's chief adviser Dominic Cummings to be removed from his role following the Supreme Court's decision.
"The calling of a Queen's Speech and prorogation is the worst political decision ever," he tweeted. "Dominic Cummings must go."
Mr Johnson was asked whether he was nervous about the Supreme Court judgment in an interview in New York, and replied: "It takes a lot to make me nervous these days. "All I can tell you is that I have the highest regard for the judiciary in this country, I will look at the ruling with care."
He was questioned by reporters on the flight to New York over whether he would resign if the Government lost.
"I will wait and see what the justices decide, the Supreme Court decides, because as I've said before I believe that the reasons for ... wanting a Queen's speech were very good indeed," he said.
He refused to rule out shutting Parliament for a second time before the October 31 deadline.
Asked if he would rule it out the Prime Minister replied: "I'm saying that Parliament will have bags of time to scrutinise the deal that I hope we will be able to do."
The Prime Minister advised the Queen on August 28 to prorogue Parliament for five weeks, and it was suspended on September 9 until October 14.
Those who brought legal challenges argue the prorogation is designed to prevent parliamentary scrutiny of the UK's impending exit from the EU on October 31.
The Supreme Court heard appeals over three days arising out of separate legal challenges in England and Scotland, in which leading judges reached different conclusions.
At the High Court in London, Lord Chief Justice Lord Burnett and two other judges rejected campaigner and businesswoman Gina Miller's challenge, finding that the prorogation was "purely political" and not a matter for the courts.
But in Scotland, a cross-party group of MPs and peers led by SNP MP Joanna Cherry QC won a ruling from the Inner House of the Court of Session that Mr Johnson's prorogation decision was unlawful because it was "motivated by the improper purpose of stymieing Parliament".
Mrs Miller has appealed against the decision of the High Court, asking the Supreme Court to find that the judges who heard her judicial review action "erred in law" in the findings they reached.
The justices have been asked to determine whether Mr Johnson's advice to the Queen was "justiciable" - capable of challenge in the courts - and, if so, whether it was lawful.
During last week's hearing, Lord Pannick QC, for Mrs Miller, told the packed court that Mr Johnson's motive for a five-week suspension was to "silence" Parliament, and that his decision was an "unlawful abuse of power".
He argued that Mr Johnson's reasons for advising on a suspension of that length "were improper in that they were infected with factors inconsistent with the concept of Parliamentary sovereignty".
But Sir James Eadie QC argued on the Prime Minister's behalf that the suggestion the prorogation was intended to "stymie" Parliament ahead of Brexit was "untenable".
Mrs Miller's case is supported by former prime minister Sir John Major, shadow attorney general Baroness Chakrabarti, the Scottish and Welsh governments, and Northern Irish victims' campaigner Raymond McCord.
The justices have also been asked by the Westminster Government to allow an appeal against the decision in Scotland.
Boris Johnson was slammed as the "father of lies" in the Supreme Court for shutting down parliament.
Aidan O'Neill QC, representing the group of MPs and peers who won a case in Edinburgh, urged 11 of the UK's most senior judges in the UK to uphold the Scottish ruling.
In an impassioned conclusion he urged them: "Stand up for truth, stand up for reason, stand up for diversity, stand up for Parliament, stand up for democracy by dismissing this Government appeal and upholding a constitution governed by laws, not the passing whims of men.
"What we have with prorogation is the mother of parliaments closed down by the father of lies."
Depending on the legal basis upon which the judges reach their conclusions, Parliament may have to reconvene if Mr Johnson, who has refused to rule out a second suspension, loses the case.
Documents submitted to the court revealed three possible scenarios in the event the court rules the suspension was unlawful, two of which could see the Prime Minister make a fresh decision to prorogue Parliament.
The other outcome could see the court order Parliament to be recalled.
But Mr Johnson's lawyers urged the judges to consider the "very serious practical consequences" involved in this option, as it would require a new Queen's Speech and State Opening of Parliament.
Lawyers for Mr Johnson's opponents said Parliament should meet "urgently" after the ruling, to decide what to do in the event the prorogation is declared "null" by the court.
At the close of the hearing on Thursday, the court's president Lady Hale said: "I must repeat that this case is not about when and on what terms the United Kingdom leaves the European Union.
"The result of this case will not determine that.
"We are solely concerned with the lawfulness of the Prime Minister's decision to advise Her Majesty to prorogue Parliament on the dates in question."
The Supreme Court judgement in full:
In giving the judgment of the Court Lady Hale said:
We have before us two appeals, one from the High Court of England and Wales and one from the Inner House of the Court of Session in Scotland. It is important, once again, to emphasise that these cases are not about when and on what terms the United Kingdom is to leave the European Union. They are only about whether the advice given by the Prime Minister to Her Majesty the Queen on 27th or 28th August, that Parliament should be prorogued from a date between 9th and 12th September until 14th October, was lawful and the legal consequences if it was not. The question arises in circumstances which have never arisen before and are unlikely to arise again. It is a “one-off”.
Briefly, the Scottish case was brought by a cross party group of 75 members of Parliament and a QC on 30th July because of their concern that Parliament might be prorogued to avoid further debate in the lead up to exit day on 31st October. On 15th August, Nikki da Costa, Director of Legislative Affairs at No 10, sent a memorandum to the Prime Minister, copied to seven people, civil servants and special advisers, recommending that his Parliamentary Private Secretary approach the Palace with a request for prorogation to begin within 9th to 12th September and for a Queen’s Speech on 14th October. The Prime Minister ticked ‘yes’ to that recommendation.
On 27th or 28th August, in a telephone call, he formally advised Her Majesty to prorogue Parliament between those dates. On 28th August, Mr Jacob Rees-Mogg, Leader of the House of Commons and Lord President of the Privy Council, Mr Mark Harper, chief whip, and Baroness Evans of Bowes Park, Leader of the House of Lords, attended a meeting of the Privy Council held by the Queen at Balmoral Castle. An Order in Council was made that Parliament be prorogued between those dates and that the Lord Chancellor prepare and issue a commission for proroguing Parliament accordingly. A Cabinet meeting was held by conference call shortly after that in order to bring the rest of the Cabinet “up to speed” on the decisions which had been taken. That same day, the decision was made public and the Prime Minister sent a letter to all Members of Parliament explaining it. As soon as the decision was announced, Mrs Miller began the English proceedings challenging its lawfulness.
Parliament returned from the summer recess on 3rd September. The House of Commons voted to decide for themselves what business they would transact. The next day what became the European Union (Withdrawal) (No 2) Act passed all its stages in the Commons. It passed all its stages in the House of Lords on 6th September and received royal assent on 9th September. The object of that Act is to prevent the United Kingdom leaving the European Union without a withdrawal agreement on 31st October.
On 11th September, the High Court of England and Wales delivered judgment dismissing Mrs Miller’s claim on the ground that the issue was not justiciable in a court of law. That same day, the Inner House of the Court of Session in Scotland announced its decision that the issue was justiciable, that it was motivated by the improper purpose of stymying Parliamentary scrutiny of the Government, and that it, and any prorogation which followed it, were unlawful and thus void and of no effect.
Mrs Miller’s appeal against the English decision and the Advocate General’s appeal against the Scottish decision were heard by this court from 17th to 19th September. Because of the importance of the case, we convened a panel of 11 Justices, the maximum number of serving Justices who are permitted to sit. This judgment is the unanimous judgment of all 11 Justices.
The first question is whether the lawfulness of the Prime Minister’s advice to Her Majesty is justiciable. This Court holds that it is. The courts have exercised a supervisory jurisdiction over the lawfulness of acts of the Government for centuries. As long ago as 1611, the court held that “the King [who was then the government] hath no prerogative but that which the law of the land allows him”. However, in considering prerogative powers, it is necessary to distinguish between two different questions. The first is whether a prerogative power exists and if so its extent. The second is whether the exercise of that power, within its limits, is open to legal challenge. This second question may depend upon what the power is all about: some powers are not amenable to judicial review while others are. However, there is no doubt that the courts have jurisdiction to decide upon the existence and limits of a prerogative power. All the parties to this case accept that. This Court has concluded that this case is about the limits of the power to advise Her Majesty to prorogue Parliament.
The second question, therefore, is what are the limits to that power? Two fundamental principles of our Constitution are relevant to deciding that question. The first is Parliamentary sovereignty - that Parliament can make laws which everyone must obey: this would be undermined if the executive could, through the use of the prerogative, prevent Parliament from exercising its power to make laws for as long as it pleased. The second fundamental principle is Parliamentary accountability: in the words of Lord Bingham, senior Law Lord, “the conduct of government by a Prime Minister and Cabinet collectively responsible and accountable to Parliament lies at the heart of Westminster democracy”. The power to prorogue is limited by the constitutional principles with which it would otherwise conflict.
For present purposes, the relevant limit on the power to prorogue is this: that a decision to prorogue (or advise the monarch to prorogue) will be unlawful if the prorogation has the effect of frustrating or preventing, without reasonable justification, the ability of Parliament to carry out its constitutional functions as a legislature and as the body responsible for the supervision of the executive. In judging any justification which might be put forward, the court must of course be sensitive to the responsibilities and experience of the Prime Minister and proceed with appropriate caution.
If the prorogation does have that effect, without reasonable justification, there is no need for the court to consider whether the Prime Minister’s motive or purpose was unlawful.
The third question, therefore, is whether this prorogation did have the effect of frustrating or preventing the ability of Parliament to carry out its constitutional functions without reasonable justification. This was not a normal prorogation in the run-up to a Queen’s Speech. It prevented Parliament from carrying out its constitutional role for five out of the possible eight weeks between the end of the summer recess and exit day on 31st October. Proroguing Parliament is quite different from Parliament going into recess. While Parliament is prorogued, neither House can meet, debate or pass legislation. Neither House can debate Government policy. Nor may members ask written or oral questions of Ministers or meet and take evidence in committees. In general, Bills which have not yet completed all their stages are lost and will have to start again from scratch after the Queen’s Speech. During a recess, on the other hand, the House does not sit but Parliamentary business can otherwise continue as usual. This prolonged suspension of Parliamentary democracy took place in quite exceptional circumstances: the fundamental change which was due to take place in the Constitution of the United Kingdom on 31st October. 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.
No justification for taking action with such an extreme effect has been put before the court. The only evidence of why it was taken is the memorandum from Nikki da Costa of 15th August. This explains why holding the Queen’s Speech to open a new session of Parliament on 14th October would be desirable. It does not explain why it was necessary to bring Parliamentary business to a halt for five weeks before that, when the normal period necessary to prepare for the Queen’s Speech is four to six days. It does not discuss the difference between prorogation and recess. It does not discuss the impact of prorogation on the special procedures for scrutinising the delegated legislation necessary to achieve an orderly withdrawal from the European Union, with or without a withdrawal agreement, on 31st October. It does not discuss what Parliamentary time would be needed to secure Parliamentary approval for any new withdrawal agreement, as required by section 13 of the European Union (Withdrawal) Act 2018.
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.
The next and final question, therefore, is what the legal effect of that finding is and therefore what remedies the Court should grant. The Court can certainly declare that the advice was unlawful. The Inner House went further and declared that any prorogation resulting from it was null and of no effect. The Government argues that the Inner House could not do that because the prorogation was a “proceeding in Parliament” which, under the Bill of Rights of 1688 cannot be impugned or questioned in any court. But it is quite clear that the prorogation is not a proceeding in Parliament. It takes place in the House of Lords chamber in the presence of members of both Houses, but it is not their decision. It is something which has been imposed upon them from outside. It is not something on which members can speak or vote. It is not the core or essential business of Parliament which the Bill of Rights protects. Quite the reverse: it brings that core or essential business to an end.
This Court has already concluded that the Prime Minister’s advice to Her Majesty was unlawful, void and of no effect. This means that the Order in Council to which it led was also unlawful, void and of no effect and should be quashed. This means that when the Royal Commissioners walked into the House of Lords it was as if they walked in with a blank sheet of paper. The prorogation was also void and of no effect. Parliament has not been prorogued. This is the unanimous judgment of all 11 Justices.
It is for Parliament, and in particular the Speaker and the Lord Speaker to decide what to do next. 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.
It follows that the Advocate General’s appeal in the case of Cherry is dismissed and Mrs Miller’s appeal is allowed. The same declarations and orders should be made in each case.
