When the Prime Minister of Great Britain and Northern Ireland accused the Leader of Her Majesty’s Loyal Opposition of telling “a whole load of rubbish jokes" you could tell another week had gone by in the British body politic. And what a week it was as MPs gathered in the Commons chamber for the regular taking of the government’s temperature masquerading as Prime Minister's Questions.

When Harold Wilson declared a week "a long time in politics" he could not know that. 40 years on, former government chief whip Andrew Mitchell would be living, if that’s the right word, proof. Just seven days ago, "Thrasher" sat squirming as Ed Miliband described him as "toast" and his PM professed undying devotion. Fast forward a week, and there were scorch marks where he once sat.

In his place, a rather surprised Sir George Samuel Knatchbull Young 6th baronet, who just six weeks ago had been pensioned off by the same PM who needed his old job as Leader of the House to dump disgraced Health Secretary Andrew Lansley. Sir George, known as a decent old cove in Tory circles, had hardly got his knitting out before being called back to the colours.

Labour’s Kevin Barron (Maltby Comp) tried to make something of the PM’s recent commitment to the masses by pointing out Sir George, like Dave, had gone to Eton, but it was clear the bicycling baronet (for whom the Downing Street cops will undoubtedly salute) was indifferent to such plebby intervention.

But Ed hardly had to bother with this sudden change of fortune as he ranged around the latest confusions and cockups which seem to mark the PM’s passage. The Labour leader came off his seat like Zebedee as Speaker Bercow sounded the bell on the weekly clash where questions asked are never answered and answers given where never questioned. Having demanded an explanation to last week’s energy tariffs fiasco , where the PM had promised benefits for all, Ed gave his own answer. It was another dodgy Dave offer. Normally the PM bats away the first few insults as he tries to hang on to the composure his advisers say should go with the job. But you could have hot-wired him straight into the National Grid and heated Milton Keynes as Ed found his chakra and poked it with a stick. The Prime Minister turned into a shouty version of the BBC’s George Entwistle as he tried and failed to cope with Ed’s onslaught. What about the West Coast main-line, he shouted, to the delight of Labour and the increasingly nervous noise of the Tories.

Chancellor George tried to help out “from a sedentary position” (which is Commons-speak for sitting down) only to be denounced with delight by Ed for his part in the first class ticket fiasco. With the noise in the chamber dangerously close to shaking the Deputy PM out of his slumber of indifference, the Speaker had to produce his own pogo-stick to remind MPs of the rules of engagement. But by now, the Labour leader was enjoying himself too much to stop. “The crimson tide is back,” he said referring to the PM’s now accepted habit of displaying the hues of autumn everywhere above his collar. Dave did try a rather strangulated defence of the question not asked about the economy, revealing that tomorrow’s growth figures for the last quarter will be as good as forecast, but the cheers from his side were lost in the jeers from the other.

With Dave in the doldrums, eyes do stray up and down the government front bench to see who the runners and riders of any future challenge might be. Despite their appearance as nodding dogs every time the PM spoke, most of his cabinet was there to be seen, including Home Secretary Theresa May. She is the latest to be shown in the parade ring, qualifying for so far avoiding departmental meltdown and pressing the right Europe buttons. But her head was bouncing in dutiful sequence with the rest as a relieved Dave, not to mention his party , finally came to the end of the Ed-banging.

As PMQs tried to get back to proper business, Labour’s Tom Watson, scourge of the Murdochs, asked about a file on a paedophile ring which included references to a parliamentary aide to a former Prime Minister. No jokes in this.