Donald Macintyre's Sketch: Vince Cable grilled over Royal Mail sell-off, but he seems to enjoy it

Impressively engaged, these folk in Middlesbrough South. Late in the Commons exchanges on the Royal Mail sell-off, their Labour MP Tom Blenkinsop announced that “I, like my constituents, am very angry that figure 20 on page 48 of the [National Audit Office report] shows that one priority investor was allocated just shy of 20 million shares and has since sold 97 per cent of them... Were they given priority because they are mates of the Government?”

Since the report was only released at midnight, this raised the ominous spectre of an aghast, if bleary-eyed Teeside citizenry furiously swapping notes on their way to work after spending the small hours poring in mounting fury over its 58 pages, including appendices.

It certainly underlined what Vince Cable was up against. When an NAO report has confirmed that taxpayers were short-changed by ministers’ “deep caution” and that some big investors broke a deal to stay in it for the long term, being dragged to the Commons by Labour’s starry Chukka Ummuna sounds about as appealing as being waterboarded in a CIA safe house.

Which made it the more striking that Cable almost seemed to enjoy it. If the real test of a politician’s mettle is shown when he’s backed up against the wall, then the Business Secretary passed it with some aplomb. True, he had carefully selected the good bits from the NAO report, which, he told MPs, “confirms we achieved our primary objective of securing the sale of shares...” This is a bit like theatre managers filleting criticism of a new play for the billboards: “An inventive idea” – shorn of the succeeding words: “disastrously executed by a hopeless cast.”

And Ummuna, by a long way the best-dressed man in the Commons, produced a serviceable denunciation of a “first-class disaster for the taxpayer”. But somehow, Cable, thanks partly to his laid-back, conversational style, emerged unscathed. He is helped by the lack of a cigarette paper’s difference throughout the rumpus with his Tory deputy Michael Fallon, who sat loyally by his side. (The leftish Lib Dem Cable and the proto-Thatcherite Fallon form, at least on this issue, one of the more unexpected conscious couplings in the Coalition.)

Was he saying, asked Labour’s indignant Steve McCabe, that this was a “personal political triumph”? Confidently Cable replied: “Yes, it was a success.” But only after failing to hear the question the first time. Or affecting to. Could he have asked McCabe to repeat the question just for the pleasure of hearing it twice?