“People have got to know whether or not their President is a crook,” Richard Nixon told reporters one November nearly 50 years ago. “Well, I’m not a crook.”

At least one Downing Street aide has privately compared Johnson to Nixon. Behind the public bonhomie lurks private anger and suspicion. Why are people briefing against him, he asks. Who are they? 

So it’s hard not to read his declaration in Glasgow on Wednesday afternoon that the UK isn’t a corrupt country in a Nixonian spirit. 

It came during a press conference that was supposed to be about his heroic dash to save the COP26 climate talks, but will be remembered for his struggle to escape from sleaze. 

There was a long, long opening statement about the talks, full of hard yards, nuts and bolts, final furlongs an balls crossing lines. We might go into extra time, apparently. Though for all his pleas of urgency, he wasn’t going to hang around and do anything himself — he had to get the train back to London. 

Being chief whip for Boris Johnson is closer to being a mafia enforcer than being Archbishop of Canterbury

When it came to questions, there was throat-clearing about the climate, but the thrust was all sleaze. So far he had simply run away from questions about this. How would he cope now? Apologise? Explain? 

We didn’t have to wait long to find out. There was a long tradition, Johnson explained, of MPs working as “doctors or lawyers or soldiers or firefighters or all sorts of other trades and callings”. He didn’t mention “corporate lobbyist”, but the implication seemed to be that it was in the list too. This had, he said “strengthened” our democracy. But it was “crucial that MPs follow the rules”. People who didn’t “should of course face sanctions”.

The strategy, then, was going to be to brazen it out. There would be no acknowledgement that he had, only a week earlier, personally ordered an attempt to stop a rule-breaker from facing sanctions. There would be no regret. There would be discussion about how others should behave, but no acknowledgement that he has always, very obviously, viewed rule-followers with complete contempt.

He was asked about Geoffrey Cox, Parliament’s international man of cupidity. “I don’t want to comment on individual cases,” he said, as though we weren’t there because of his very strong desire to get involved in an individual case. “It wouldn’t be right for me. It wouldn’t be appropriate.”

Cox had earlier revealed that the Chief Whip had signed off his lucrative jaunt to the Virgin Islands. But being chief whip for Boris Johnson is closer to being a mafia enforcer than being Archbishop of Canterbury. Just because the Chief gives something the thumbs up, it doesn’t make it right or wise, as Tory MPs learned the hard way last week.

Was Johnson confident his own behaviour would stand up to scrutiny? “All my declarations are in conformity with the rules and you can certainly study them,” he said, in a line that had the air of having been drafted in consultation with lawyers. It is, again, worth emphasising how very hard he has tried to keep secret details of recent freebies, whether it was holidays or wallpaper.

British prime ministers should know they have a problem when they’re insisting their country is basically honest

As the questions kept coming, he seemed to have a moment of clarity, a realisation of how this all looks. “Since we’re in an international context and speaking before international colleagues,” he said, “I just want to say one thing which I hope is not taken in a chauvinistic spirit. But I genuinely believe the UK is not remotely a corrupt country. Nor do I believe our institutions are corrupt. It’s very, very important to say that.”

This is not quite correct. It’s actually very, very important not to have to say that. Just as American presidents know they’re in trouble when they’re explaining they’re not criminals, British prime ministers should know they have a problem when they’re insisting their country is basically honest.

How embarrassing is it that our prime minister has to reassure foreign journalists that we’re not corrupt? How embarrassing that he personally is the reason the questions is being asked? How embarrassing that his assurances are not terribly convincing?

At points in Johnson’s career, he has had to be bailed out by the boring, honest losers whom he so despises. Now, having personally dragged the nation into the gutter, he was pleading, in his defence, the long history of good behaviour of the rest of us.

Johnson has always ultimately got away with his behaviour because everyone else has let him, from his fellow hacks to his fellow MPs to the voting public. Rather as his speeches are only funny to an audience that is expecting to laugh, his excuses only work with people who are willing to be indulgent. There was in Glasgow a hint, perhaps, that patience is running out.