Theresa May entered the Chamber at 11.54 looking dangerously happy. Philip Hammond looked happy too. They shared a joke.

Chris Philp, the trusty MP for Croydon South, rose and asked for a White Paper on the plans for Brexit. One or two of us thought for a moment that Philp had turned into a rebel, a doughty defender of the Commons’ right to hold the Executive to account, for we were under the impression that the Prime Minister had refused to issue a White Paper.

How insulting of us to doubt even for a moment Philp’s loyalty. For the Prime Minister rose and announced that the Government’s plans “will be set out in a White Paper”.

Three rows behind May, Kenneth Clarke was laughing now. He looked delighted, and also appreciative of the cool effrontery with which, in broad daylight, the Prime Minister had executed her U-turn.

Jeremy Corbyn rose. He asked “when the White Paper is going to be available”.

The Prime Minister rocked back with laughter, raising her foot off the ground. When it was again her turn to speak, she pointed out that Corbyn “always asks about process”, while she is “focussing on the outcome” of the Brexit talks.

A U-turn is often embarrassing. It exposes the U-turner to charges of weakness, cowardice, inconsistency, even panic.

But May’s U-turn was so palpably what the House wanted that it redounded to her credit. One could not help wondering if she had saved it up, so she could at a helpful moment make this concession to public opinion.

If Corbyn were quicker on his feet, he could have mocked the Prime Minister. He could have said she had adopted an indefensible position, which she was now being forced to abandon.

But Corbyn is not quick. He is a prisoner of his script, which contained the charge that May wants to turn Britain into “a bargain basement tax haven off the coast of Europe”.

Somehow he couldn’t make the phrase sing. The gap between his bargain basement and May’s correct, front-parlourish manner was too wide for him to leap.

The Tories jeered him, while his own troops heard him in despondent silence. They know he is not up to it. May walks all over him.

One day she will stumble, for that is the nature of politics. But the only contribution Corbyn is ever likely to make to that stumble is to encourage her to become over-confident.

Corbyn also managed, during this PMQs, to express his condolences about a police officer in Northern Ireland who “lost his life”. The officer in question is still alive.

So is Corbyn’s predecessor, Ed Miliband, who suggested that when May meets Donald Trump, she should “offer the services of UK scientists” to the new President, in order to persuade him that “climate change is not a hoax invented by the Chinese”.

We did not think we would ever write, “Bring back Ed Miliband”. But he would be a clear improvement on the present Leader of the Opposition, whose main ability is to make his own side look feeble.

Now that May has promised a White Paper, Corbyn should have the decency to run up the white flag.