The moment when Ed Miliband started to strain credulity was when he asserted that “the whole country will want an answer” to the question of whether Gus O’Donnell raised concerns with David Cameron about the appointment of Andy Coulson. The whole country has never heard of O’Donnell, the former Cabinet Secretary. Nor would the whole country be interested in what O’Donnell said on this topic even if he had said anything at all, which he rather implies in the written evidence he submitted to the Leveson Inquiry that he did not.

Labour strained every sinew at PMQs to catch the Prime Minister out on some such arcane point of detail. Cameron had arrived well briefed for this. He did not attempt, in an arrogant fashion, to brush the accusations away with a few airy jibes. His manner was that of a dour batsman who is determined to give the bowlers no chance.

Miliband toiled away, but could get nowhere. In his final attack, he accused Cameron of being the first ever Prime Minister “who brought a criminal into the heart of Downing Street”. This will be news to the whole country to which Miliband had just appealed. The whole country thinks pretty much everyone who is brought into Downing Street is a criminal. That is our traditional view of politicians. The idea that such larger-than-life figures as Lloyd George and Churchill never brought anyone disreputable into Downing Street is ridiculous. Even Neville Chamberlain relied on the services of Sir Joseph Ball, who admittedly worked from Conservative Party premises, but who had wide experience “in the seamy side of life and the handling of crooks”, and beside whom more recent prime ministerial assistants look like babes in arms.

Tory backbenchers rallied round Cameron to support him against the intolerable self-righteousness of Labour. Perhaps his most striking assistance came from Philip Davies (Con, Shipley), who usually misses no chance to make life awkward for the Prime Minister. Davies pointed out that no one had produced the slightest evidence in 2009 or 2010 that Coulson knew anything about phone-hacking.

Cameron replied, with mingled pleasure and surprise: “I think my honourable friend put it rather better than I did.”

Labour wanted so much to make a success of this session, and it failed. Chris Bryant (Lab, Rhondda) asserted in a fury that “the Prime Minister’s only sorry because he’s got caught”. One might equally well say Labour was only sorry because it had failed to catch the Prime Minister out.