In autumn 1977 Paul Johnson wrote a memorable article for the New Statesman explaining why he could no longer support Labour. “One reason why I joined the Labour party,” he wrote, “was that I believed it stood by the helpless and persecuted, and by the angular non-conformist.” For him, Labour no longer did this – thanks to trade union corporatism from below, and Marxist intellectuals above.

I was an undergraduate at the time, and this article changed my political outlook so profoundly that I can recall the moment I read it. As for Paul Johnson, a giant of literary and political journalism, his timing was sublime. He called the moment when Labour, which in 1977 seemed the natural party of government, embarked on its journey to irrelevance and worse.

Forty-two years later, the Conservative Party is open to the same despairing verdict. The Conservatives have become a vehicle for well-drilled fanatics who, like the Militant tendency forty years ago, infiltrate constituency parties in order to deselect MPs who offend doctrinal purity.

There is no more Conservative figure than Dominic Grieve, the former attorney general. His offence? Standing up for parliamentary democracy and the rule of law. These are, it seems, hanging offences in Boris Johnson’s Conservative Party.

The prime minister, who is one of the most brilliant men to enter Downing Street, ought not to need reminding that the Conservative Party came into existence in the wake of the French Revolution as a defender of institutions – church, monarchy, parliament, rule of law – against abstraction, ideology and ultimately political violence.

But Johnson’s new Conservatives have abandoned these origins, and become a sect. They have detached themselves from the everyday concerns of ordinary people and are waging a destructive war on the British system of government.

Johnson’s Downing Street has been hostile to Parliament and contemptuous of the civil service. It has humiliated the Cabinet, mocked due process, repudiated the rule of law, made light of monarchy and played games with the integrity of the United Kingdom.

This government is not simply un-conservative. It is an explicit repudiation of everything that it means to be a Conservative.

Constitutional vandalism, and dark money

When I was political correspondent at The Spectator magazine under Boris Johnson’s editorship at the start of this century, we mercilessly analysed and exposed the constitutional vandalism of Labour’s Prime Minister Tony Blair. Now Johnson, counselled by his amoral, dangerous ‘senior adviser’ Dominic Cummings, has been doing exactly the same.