This is a constitutional crisis

The police have today concluded that Boris Johnson, the Chancellor and the PM’s wife all attended illegal parties that breached Covid laws written by the PM. This is most serious for the prime minister of the three of them because it was he who told MPs on 8 December that he had been ‘repeatedly assured’ there were no parties and that no Covid rules were broken.

He now has the challenge of his life to prove that he did not willfully and knowingly mislead MPs – because if he did deliberately mislead MPs then he has no choice but to resign under the code of conduct for ministers, which he signed off and approved in keeping with normal practise on becoming PM. This is perhaps the most important test of the robustness and efficacy of the checks and balances in the British constitution of my lifetime.

If Tory MPs unthinkingly keep him in office without a proper and public assessment of how parliament was misled, because that is what suits them, and if they blithely ignore the ministerial code, then the charge will stick that this or any party with a big majority is simply an elected dictatorship and the constitution means little or nothing.

This is not just a slippery slope. It is the bottom of the slope.

Listen to Fraser Nelson, Katy Balls and Isabel Hardman on the latest episode of Coffee House Shots: