It was a day of history, or even hysteria, at Westminster and the most hysteric moment of all came at 12.31pm when the Speaker, Little Johnnie Bercow, told MPs that he had picked Professor Sir Ian Kennedy to head the Independent Parliamentary Standards Authority, the new body to control their expenses.

“His appointment must be confirmed by the House of Commons,” said Mr Bercow, each word emitted with a little puff of pomposity. “He will be paid a maximum of £100,000 . . .”

Paroxysms! Screams and whoops filled the chamber. “Outrageous!” fumed Tory grandee Sir Nicholas Winterton, as red as a sunset.

“Order!” beseeched Little Johnnie, crouching in his chair.

“He’s paid what?” cried Sir Nicholas, mouth in a wide “O” of outrage. A Labour MP gave a three-finger salute, we must assume for a three-figure salary. Other MPs shouted something about his expenses (“expenses” is like a swear word now).

“Order!” pleaded Little Johnnie, who would shout it a total of nine times before giving up. “We are fortunate,” he screamed, “to have such an eminent candidate!”

This brought more unrest.

It was a day of horror in Afghanistan, of fudge for Tory Euro policy and of austerity in the form of Sir Christopher Kelly’s report on parliamentary expenses. But that outburst in the chamber was the most revealing: it was mutiny, pure and simple, a looking-glass moment when MPs’ hurt and anger erupted into 60 full seconds of mocking laughter. It was wrong on so many levels but, for one tantalising sweet minute, they didn’t care.

The whole day was organised like a play (which, tentatively, I have entitled They Just Don’t Get It!).

Act One was at 10am when the patrician figure of Sir Christopher, standing in front of a sign that set out the seven characteristics of public life, which began with “selflessness”, said that, in future, MPs could not employ their wives or husbands or have their mortgage interest paid for them. Indeed, he said, they will have to hand back any taxpayer-funded capital gains from the sale of a home.

I could almost see MPs rushing to their pocket calculators. Out came the envelopes, the pencils, the phone calls over whether it made sense to sell now before the rules come in. (Sir Christopher believes that his rules came in as of 10am yesterday but that goes to show how little he knows about how the real world of Westminster really works.) During PMQs (Act Two), MPs must have had to physically sit on their hands to stop doing calculations. The Prime Minister and David Cameron were sombre about Afghanistan, and Nick Clegg, for the first time, seemed to signal that he may come out against the war. The PM tried to mock Mr Cameron over what had been his “cast-iron” promise for a European referendum but, every time, the PM said “iron-cast” instead. The joke was, as usual, on him.

Act Three starred Harriet Harman (no, you can’t go and get an ice cream now) who gave a statement on expenses during which most MPs left the chamber to obsess about their mortgages in private. The ones who remained thought the expenses scandal could mean only one thing: now was the time to review (and up) their piddling annual salaries of £64,766. “So that in the longer term we can marry pay structures with allowances in such a way that the dreadful allowances system is abolished for all time,” announced Labour grandee Sir Stuart Bell, “and we can get back to discussing Afghanistan!”

Indeed. And pigs will fly too.

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