In september 1995 Boris Johnson, a rising star of the Daily Telegraph’s comment pages, spent an evening with the Dulwich Labour Party. His trip to the south London suburb was an act of anthropology, undertaken to study a new tribe: the educated middle classes who had fallen hard for Tony Blair. Mr Johnson’s hosts plied him with Bulgarian red wine and taco crisps, and raged at the dying Conservative government. He was an observant visitor, recalls John McTernan, his chaperone and a future aide to Mr Blair.

Mr Johnson was a keen student of New Labour, whose era coincided with his own ascent to prominence. He was repelled by its “bare-faced quasi-messianic effrontery”, “spin-driven vanilla-flavoured candyfloss nothingness”, and assaults on fox-hunters and smokers. But he was mesmerised, too, for Mr Blair was a winner. Mr Johnson watched how “Supertone” ransacked the Tory wardrobe, played the press “like a master organist” and imposed a new doctrine on his party. (“In the game of political repression, the Burmese police have little to teach New Labour.”) As the years went on, scandals and sleaze seemed not to touch his popularity. In 2002, now editing the Spectator, a Tory-leaning weekly, Mr Johnson named Mr Blair parliamentarian of the year, hailing his “unchallenged dominance of the political landscape”.