The Supreme Court has unanimously held that the Government’s prorogation of Parliament was unlawful.
As set out previously, the Government had sought to suspend, or ‘prorogue’ Parliament, meaning that Parliament would not sit from 10 September until 14 October. According to an earlier House of Commons Library paper, prorogation “is the means (otherwise than by dissolution) by which a Parliamentary session is brought to an end”. It has generally been regarded as a formality and often happens in the autumn – and the current session of Parliament has already lasted longer than is usual. An effect of prorogation is that it brings to an end all proceedings in the current Parliamentary session and unless specific provision is made, no business of a previous Parliamentary session may be carried over into the next session.
The stated reason for the proposal had been to schedule a Queen’s speech for a new session of Parliament, which would set out proposals for a new legislative agenda.
The power to prorogue Parliament is a “prerogative power”. This means it is a power which is vested in the Government and which can be exercised without a requirement for Parliamentary consent. The Government argued that, as an exercise of prerogative power, the decision to prorogue was not justiciable. However, the Supreme Court disagreed and therefore the courts have jurisdiction to decide upon the existence and limits of a prerogative power. According to the summary of the decision, the limit of the power is that a decision 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”. As a result, the motive for the prorogation did not need to be considered.
In the Supreme Court’s view, the prorogation 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 Supreme Court concluded by holding that the purported prorogation was void and of no effect and as a result, Parliament has not been prorogued. As a result, Parliament is expected to reconvene shortly.