Cowardly, untrustworthy, disrespectful, unmanly, slinking into office through the back door. Thus did Tory leadership candidate Jeremy Hunt describe his rival Boris Johnson. And that, as the historian Edward Gibbon said of a dodgy pope, was Hunt declining to mention “the most scandalous charges”.

A nocturnal spat, supposedly over a wine stain, between Johnson and his girlfriend, Carrie Symonds, in a Camberwell flat, is of no public concern, merely public fascination. Downing Street has no nosy neighbours. But as Michael Gove discovered over cocaine, when standing for public office you cannot pick and choose what interests the public. Unfairness is part of the game. It is for others to judge whether Johnson’s screaming fits with his partner in love augur well or ill for his partners in office.

More to the point is Hunt’s prime charge. Johnson is clearly hiding from scrutiny. Since he cannot qualify as prime minister by dint of competence, he must rely on charisma. No man confident of high office allows himself to be hidden for weeks in a cupboard by the likes of Lynton Crosby. What is it about Johnson that so frightens Crosby – defamation, embarrassment, hypocrisy, the truth?

Boris Johnson’s pitch is all about his character. That’s why the row in his flat matters | Matthew d’Ancona Read more

The failings of the Tory leadership process are glaring. The final round of MPs’ votes was as rigged as a Russian presidency. Ninety MPs who did not bother to turn up were allowed to vote by proxy, a blatant abuse that eliminated Michael Gove, the more serious challenger to Johnson. The 1922 Committee should have instantly disallowed the vote. Now Johnson’s team is trying to shut down any exposure that might give a smidgeon of hope to Hunt. This is not a dignified path to Downing Street.

Hunt is a poor alternative. His stated views on everything from standing “shoulder to shoulder” with America in Iran, to tipping cash into Tory vanity projects such as Heathrow and HS2 are depressingly conventional. He shows not an ounce of originality. But on Brexit he talks the language of the sane. Johnson simply lies. He knows he cannot renegotiate a new withdrawal agreement by 31 October. He knows there will then be no legal alternative to a tariff wall and a barrier with the EU. He is like a creationist preacher, ranting from the holy book of Brexit, against all evidence to the contrary.

Hunt rightly says this is ridiculous and reckless. As the BBC’s Panorama will explain this evening, it would almost certainly mean a no-confidence vote and the Tories’ and Johnson’s possible fall from office. That at least should concentrate the minds of Tory party members over the coming month. As the irresistible force of Johnson hurtles towards the immovable object of the Brexit deadline, we await the screeching of brakes or a deafening crash.

Hunt is a screeching of brakes. Dull, boring, unexciting he may be, but he would face what is a looming crisis with realism. Everything now hangs on those Tory members. Will they find the Johnson glamour finally pales before evidence of the Johnson reality? Will Britons soon rise to salute that wine stain on a Camberwell sofa?

• Simon Jenkins is a Guardian columnist