One former Downing Street insider suggested on Tuesday night that the Prime Minister could call Mr Sunak’s bluff by suddenly announcing to the House that he had decided to scrap the health and social care levy, a move guaranteed to win over backbenchers and swathes of the general public.

“The only trouble is that would require the sort of forward thinking that Number 10 currently seems to lack,” the source added.

In a rare moment of acuity, Sir Ed Davey, the Liberal Democrat leader, summed up the problem for the opposition by saying: “No other leader in any other organisation would be allowed to continue after law-breaking on this scale.”

Indeed not. Because Mr Johnson is unlike any other leader. No other leader, after walking the streets of Ukraine with Volodymyr Zelensky at the weekend, would prompt the war-torn country’s parliament to declare to the world: “Be brave, like Boris.”

So if it had not been for Ukraine, the cost of living crisis and Mr Sunak’s sudden fall from grace, Mr Johnson would undoubtedly be under much more pressure to step down right now.

But the Prime Minister has been having a good war, even if the surveys suggest he is losing the battle on the home front.

His hero Sir Winston Churchill famously said that “failure is not fatal, it’s the courage to continue that counts”. Yet will the British public view Mr Johnson as “brave” for clinging on to power?

Some certainly will – and there is no denying that the Prime Minister retains a significant fan base which, having already priced in his casual relationship with the truth, regards him as the victim of a witch-hunt.

Others will rightly point out that the Covid rules were ridiculous in the first place, clinging on to the hope that a Prime Minister hoist by his own petard will be less liberal with his dispensing of our civil liberties in future.