In a unanimous verdict, the judges said the prorogation was “unlawful, void and to no effect.”
Announcing the verdict, Supreme Court president Lady Hale said: "The court is bound to conclude 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 prolonged suspension of parliamentary democracy took place in quite exceptional circumstance.
The effect on the fundamentals of our democracy was extreme.
House of Commons speaker John Bercow was one of the first to respond “welcoming” the decision.
Responding to the ruling immediately, he said: "I welcome the Supreme Court’s judgement that the prorogation of parliament was unlawful.
The judges have rejected the government’s claim that closing down parliament for five weeks was merely standard practice to allow for a new Queen’s Speech.
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. As the embodiment of our parliamentary democracy, the House of Commons must convene without delay. To this end, I will now consult the party leaders as a matter of urgency.
The decision is dividing the country, with some people agreeing that Boris's decision to prorogue government was indeed unlawful, whilst others are arguing that the Supreme Court's decision is preventing government from doing its job.
Many agree with the decision that proroguing was "unlawful" and they are calling on Boris Johnson to resign
We already knew you are dishonest.
The highest Court in the land has now ruled that you are law… https://t.co/pU328FcFoC