“This must be the Oxford Union debating skills we heard so much about,” Sir Keir Starmer remarked in a derisive tone.

Like so many of the Prime Minister’s opponents, the Leader of the Opposition feels an irresistible urge to write him off as a stereotype, a caricature, a Bertie Wooster of a politician, unable to cope with the modern world and easily finished off by such a masterful contemporary figure as Sir Keir Starmer.

If Johnson was as useless as that, he would never have been selected by Henley Conservatives to succeed Michael Heseltine; would never have beaten Ken Livingstone to become Mayor of London; and would not have had the slightest hope of winning a general election at which many former Labour voters in northern seats lent him their personal support.

Sir Keir had another go: “He’s an ostrich, perfectly happy keeping his head in the sand.” Another ridiculous under-estimate of his opponent. No one saw more quickly than Johnson how the free world should react to the Russian invasion of Ukraine.

On other issues too, Johnson does not yet suffer from the blindness and deafness which come to those who have been too long in power.

Sir Keir began by expressing the hope that Johnson had shown there was “no place for sexism or misogyny” in the Tory party.

Johnson had moved several days ago to defend himself in that quarter. He said there was “absolutely no place for sexism or misogyny”, and added that he had “exchanged messages with the Right Honourable Lady over the weekend, and I repeat what I said to her, there can be absolutely no place for such behaviour”.

Angela Rayner sat in black, a sombre figure, the woman about whom the story had been published. If this were the Oxford Union of the 1980s, when Johnson at his second attempt became its president, one can be confident that jokes in poor taste would have been tried out by at least some of the speakers.

At Prime Minister’s Questions in the 2020s, absolutely nobody indulges in such career-ending behaviour.

Sir Keir has been accused by some of his colleagues of getting obsessed by Partygate. He therefore asked about the cost of living crisis, during which, he added, “the Tory Party’s had its head in the sand”.

Again, an underestimate: behind Johnson is found no Ostrich Party, but a gang of assassins watching with the keenest attention how their leader is getting on, and whether the nation still wants him.

They made a certain amount of noise on his behalf, and avoided saying anything downright disloyal, for the local elections are coming up. But for most of the time one cannot say they listened with great enthusiasm to him.

“This guy is doomed to be a permanent spectator,” Johnson said of Sir Keir at the end of their exchanges: a slightly more Oxford Unionist remark, but still nothing like as rude as the real thing.

To Ian Blackford, the SNP leader, Johnson said: “I wouldn’t like to bet on him outlasting me, Mr Speaker.”

Blackford laughed, but this was, in its way, a recognition of prime ministerial mortality. No one knows how soon PMQs will get a new cast.