Q1: Is the lawfulness of the Prime Minister’s advice to Her Majesty to prorogue Parliament justiciable?
YES. The courts have exercised a supervisory jurisdiction over the lawfulness of acts of the Government for centuries. This case was about the limits of the power to advise Her Majesty to prorogue Parliament.
Q2: What are the limits to that power?
Two fundamental principles of our Constitution are relevant to deciding that question.
- a) 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.
- b) 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”.
Therefore “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.”
Q3a: Did prorogation have the effect of preventing Parliament from carrying out its normal functions?
YES, it did have that effect. It was not a normal prorogation. Difference between Parliament being in recess (when Parliamentary business can continue) and being prorogued (when it cannot) explained. In the current circumstances of major political and constitutional change, the “effect upon the fundamentals of our democracy was extreme”.
Q3b: Was it justified?
NO, because no justification for taking action with such an extreme effect had been put before the court.
CONCLUSION: The Court said it was 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.
EFFECT: The Order in Council to which it led was also unlawful, void and of no effect and was to be quashed. The prorogation was also void and of no effect. Parliament has not been prorogued.