During Boris Johnson’s run for the leadership of the Conservative party, a familiar ritual developed. Obviously, with the thing not in the bag, it was too dangerous to allow the candidate himself to face questions in any but the most supportive forums. Instead, MPs who wished to climb onto his bandwagon were sent out onto the airwaves in his place, to undergo the humiliation of admitting that they knew neither the number of his offspring nor the details of his secret plan for Brexit. 

Those who had previously expressed doubts about his suitability for high office were expected to dip their hands deepest into the sewage, explaining to Nick Robinson why they in fact believed him to be honest, diligent and competent. 

The process is now being repeated. Ministers in Johnson’s government who know nothing of his wallpaper or his partygoing find themselves asked if they find his excuses convincing. Of course they do, they reply. What more appropriate way could there be for a prime minister to spend a Sunday afternoon than texting rich people to ask them to pay his decorating bill? What filthy minds we must have to find something suspicious in his failure to reveal this exchange to the subsequent investigation.

Anyone agreeing to advise Johnson on ethics would be a fool not to get fitted for a hazmat suit

It’s all in the game, of course. They don’t have to believe it. It’s hard to imagine Johnson expects them to. His shtick, for years, has been the knowing glance to the audience, breaking the fourth wall to reassure them that he knows how ridiculous all this sounds.

It has taken him to the top. But his defenders, girding their loins to prepare for their next interview, need to remember that he’s the only one who can pull it off. 

Lord Geidt has become the latest person to sacrifice their own good name in order to keep some muck off Johnson’s. With a CV that has more than its fair share of ellipses but definitely includes a stint in army intelligence, Geidt probably feels he can take care of himself. He surely knew something like this was coming. Anyone agreeing to advise Johnson on ethics would be a fool not to get fitted for a hazmat suit.

But others before him have believed they’d be able to spend their days cleaning the Johnsonian stables and come away without a stink. They have found it harder than they expected. Take Allegra Stratton. While the circumstances of her resignation were a surprise, it was hardly a shock that Johnson’s spokeswoman ended up with her reputation trashed. As the leaked video showed, the prime minister’s denials of reality sound a lot less funny when they’re repeated by other people.

Johnson is steadily contaminating everyone involved with him. Would Downing Street civil servants have thought it wise to hold lockdown parties under another prime minister? Probably not. Would Owen Paterson’s friends have tried to get the government to change the rules?

But once you’ve hitched your wagon to Johnson, you’re stuck. People who used to be known as staunch moralists find they’ve written a column explaining why they’re unfussed about the prime minister soliciting cash from millionaires.

Turning back to this week’s scandal, receiving a sum close to the size of your annual salary from someone who wants something from your employer is not an ethical grey area. Tories who profess to admire the rigour of the private sector should consider that this is the sort of thing that merits instant dismissal from most companies. 

They won’t, though. They’ll take their turn defending things they think are wrong, and they’ll hope that, when Johnson is finally removed from office, the stink won’t linger on them or their party. 

Perhaps it won’t. But I don’t give much for Geidt’s chances of getting the smell off. There will be more revelations and more excuses, and doubtless more firm letters. This is who Johnson is, and this is what his government looks like. Another peer, Lord Nolan, gave his name to the principles of public service that politicians are supposed to follow. Perhaps Geidt will give his to the turning of blind eyes by helpful officials.