In a unanimous verdict, the court has ruled that Johnson’s decision to prorogue parliament can be examined by judges, overturning the ruling of the high court in London.
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Then, giving the court’s judgment on whether the decision to suspend parliament was legal, Hale said: “This court has … concluded that the prime minister’s advice to Her Majesty [ to suspend parliament] 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 should be quashed.
“This means that when the royal commissioners walked into the House of Lords [to prorogue parliament] 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.”
It is now up to the UK parliament to decide what to do next. Which is as it should be. In the Westminster system, the elected legislature is supreme, and the executive ultimately subordinate to it. Fortunately, this time parliament hasn't had to cut anybody's head off to prove it.
Meanwhile, if the prorogation was unlawful, then the attempt to prorogue constitutes an unlawful interference with parliament's business. And that's the very definition of contempt, and Boris Johnson and his clique should be held accountable for it.