The U.K. Supreme Court has unanimously ruled that the prorogation of Parliament was unlawful:

The panel held unanimously that Mr Johnson’s advice was unlawful because it had the effect of frustrating Parliament.

It also found the prorogation and was “void and of no effect” – meaning Parliament has not been suspended.

Lady Hale said: “The court is bound to conclude therefore that the decision to advise Her Majesty to prorogue was unlawful because it had the effect of frustrating or preventing the ability of Parliament to carry out its constitutional functions.”

The text of the judgment can be read here. The ruling from the court is a major blow for Johnson, and it very likely means the end of his ministry. Following the ruling, Parliament will return on the grounds that the prorogation was void. That was the judgment of the court:

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.

The Speaker of the House of Commons made clear that they would be returning as quickly as possible:

In reaction to the court’s decision, John Bercow, Speaker of the House of Commons, said in a written statement that lawmakers must convene as a matter of urgency. He said the ruling “vindicated the right and duty of Parliament to meet at this crucial time to scrutinize the executive and hold Ministers to account.”

As his his earlier defeats in the House proved, Johnson clearly does not have a majority on his side for anything he wants to do. He is not just the head of a minority government, but one who has also tried and failed to circumvent Parliament. The prime minister’s position has become untenable. There are already very loud calls for his resignation from the opposition, and we should expect to hear many more in the coming week.