The ruling that the suspension of parliament was unlawful is an unprecedented attack by a court on an elected Prime Minister.

His prorogation was sought for the improper purpose of avoiding parliamentary scrutiny of his Brexit policy.

It has huge implications both legal and political. In effect it says the actions of a Prime Minister can be illegal if that deed is about undermining a key plank of constitutional government of which ministerial accountability to parliament is an important pillar of our system.

The implications are damaging. Boris Johnson behaved illegally, he misled the Queen as to the intention of his prorogation, in the process bringing the monarch's neutral political position into disrepute and casting himself in the role of abuser of power.

This will send the Westminster bubble into a frenzy with the inevitable calls for the Prime Minister to resign and for the government to recall parliament immediately.

The attacks on the Prime Minister in the coming days will be ferocious. He will be damned in the court of parliamentary opinion. But with an election looming the only question that really matters in the short term is how this will play with voters. Will they see this as incontrovertible independent evidence he is unfit for office?

I suspect those strategists in Downing Street will not be losing sleep over this. Why? The Johnson narrative is already clear. I have tried to deliver Brexit and have been legislatively handcuffed by MPs. In the process I have fought my own party and taken the whip from MPs in order to deliver the will of the people. And now judges are frustrating me too.

This judgment adds to the issue he wants to dominate the election. Who governs and who is sovereign? People or parliament and the courts?

The upcoming election is going to take difficult and complex issues of governance and reduce them to slogans as parties hope to triumph by seeking popular assent for their Brexit positions.