|UKSC 24 September 2019|
It is a judgment that will resonate around the common law world in which many Parliamentary systems are based on the Westminster-model.
The court held unanimously that the advice given to Her Majesty by the Prime Minister (Boris Johnson) to prorogue Parliament was justiciable and also unlawful. The court held
that the consequence of the advice being unlawful was that the Order in Council of 28 August 2019 was also unlawful, void and of no effect and should be quashed.
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 was the unanimous judgment of all 11 Justices.
Lady Hale, said that - "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."
The Court's Judgment and Press Release are available via the following links:
R (Miller) v The Prime Minister  UKSC 41
Cherry and others v Advocate-General for Scotland  UKSC 41
The prerogative power to prorogue Parliament remains and there could be a further prorogation provided that it is reasonably justified. Whether that test is satisfactory is a matter for another day! In the light of this judgment, the days of the prerogative power ought to be numbered. It is a justiciable power and its use on this occasion and in these circumstances was ruled unlawful. It will be for Parliament to tame this potentially unruly power.