As the Conservative Party braced itself for confirmation of the ten candidates for its leadership last Monday, one of the more intelligent members of its parliamentary electorate spoke to me in terms of astonishment about the suspension of disbelief over the candidacy of the front-runner, Boris Johnson. Her tale is replicated among a number of her colleagues: the spectacle of a few dozen Tory MPs who deplored some of Johnson’s activities as mayor of London, denounced his record at the Foreign Office and derided both his personal and professional moral probity, and are now slavishly embracing him as the putative leader. But then many of the astonished are relatively new to the political game, and many of those who have declared their support for Johnson are among the more unscrupulous, unprincipled and self-serving of their kind.

Matthew Parris, in a thoughtful recent Times column, wrote of Johnson that he is “a habitual liar, a cheat, a conspirator with a criminal pal to have an offending journalist’s ribs broken, a cruel betrayer of the women he seduces, a politician who connived in a bid for a court order to suppress mention of a daughter he fathered, a do-nothing mayor of London and the worst foreign secretary in living memory”. However Parris, a former Tory MP, observed that “such truths are apparently already ‘priced in’ to Mr Johnson” and hoped that “the actual electorate are informed that his rascality is already ‘priced in’ and they’re not to bother their little heads with such horrors”. With commendable understatement, he called Johnson “a nasty piece of work” whose acolytes were already using moral blackmail to persuade people to support him. For those in the Tory party with the self-knowledge to understand what is happening, it is a moment of unprecedented and shaming awfulness.

Johnson has the support he has for a lethal combination of reasons. One is an outburst of headless chickenism among Tory MPs more extreme than any I can remember in 35 years of writing about politics, provoked by the Brexit Party’s success in the European elections. A number of MPs not supporting Johnson assume that should a general election be forced before Britain has accomplished Brexit, Nigel Farage’s new party would, one way or another, end the careers of between a third and half of them. Another reason is the belief that only a proven “winner” – the accolade some accord to Johnson for twice becoming mayor of London – can manage the threat.

No account is taken of how Johnson’s reputation has declined even further since he last won the London mayoralty seven years ago, thanks to his mendacious conduct during the Vote Leave campaign, his graphic failure as foreign secretary, and his duplicity as the constituency MP who declared he would lie down in front of the bulldozer that began construction of the third runway at Heathrow (with typical cowardice, he engineered a pointless trip to Afghanistan to avoid voting against it, at a cost to the taxpayer of more than £20,000).

But such is the tribal desperation of some Tory MPs to keep their seats that they believe Johnson can dupe the public as effectively as he has duped them, and keep them in the Commons beyond the next election. Therefore, to use Parris’s idiom, they “price in” his absence of probity, and give him their support. In their eyes he can behave as badly as he likes because he has “charisma” and “stardust”, vacuous terms used by some supporters who have nothing more analytical to say about him. They prefer not to discuss the consequences of someone with his moral failings and immense character flaws becoming prime minister.

Those shortcomings were thrown into sharper focus with the disclosures about Michael Gove’s drug-taking. Johnson has joked about trying to take cocaine; but in his case it doesn’t matter because, as has been established, he can behave as he wishes. And thus we had the paradox that a competent candidate – even Gove’s detractors admit he has an impressive record as a

minister – is humiliated for telling the truth, whereas another is elevated to leader of the pack despite being a proven liar.

Johnson’s own campaign is well aware of the dangers of his lack of honesty, competence and decency. That is why, apart from being allowed out to face some underarm bowling from the Sunday Times, he has studiously avoided the media. This, one hears, was on the advice of his new partner, who knows the perils that lurk in straight questions to which he would struggle to give straight answers. It is said one of Johnson’s supporters – the lacklustre former party chairman Grant Shapps – has told him he is “one newspaper article away from oblivion”. He could just as easily have said one question from John Humphrys or Andrew Neil, or someone of that calibre, whom he will be unable to avoid indefinitely. Johnson’s plan is that the longer he keeps silent, the easier it will be to get through to a plebiscite of the party’s membership that he, and everyone else at present, expects him to win.

There is an assumption that a Johnson victory would lead sooner rather than later to a general election. Many Tory MPs believe Labour would call a vote of confidence swiftly, hoping to capitalise on Johnson’s divisiveness in his own party and on the likelihood that he will have bitten off more than he can chew; and without eight deputy prime ministers – in the way in which, in his indolence, he had eight deputy mayors – to do his job for him. One would then see how right all those cynical Tory MPs, boasting of their support for him to ingratiate themselves with their activists or in the hope of getting on the greasy pole too, have been. If they turn out to be wrong it won’t be Johnson alone who is unforgiven.

Simon Heffer writes for the Daily and Sunday Telegraph