Tom Peck's Sketch: Jeremy Corbyn shows how to use the Government's mistakes to his disadvantage once again

The Labour leader's generous advice for David Cameron had the Tory benches collapsing with laughter

According to an ORB poll for The Independent seven out of 10 people do not trust Jeremy Corbyn to safeguard Britain’s national security (Getty)

With his possibly sacked or possibly not sacked Shadow Foreign Secretary sitting stony-faced at his side, Jeremy Corbyn generously offered the Prime Minister some advice for his ever ongoing EU renegotiations.

Accompanied as always by the deafening wall of silence from his party colleagues behind him, he cautioned: “To deliver change you need patient, effective diplomacy, and you need to make friends.”

In a building needing £6bn worth of restoration work these were dangerous words, and sure enough, half the house collapsed in an instant. The Tory benches haven’t laughed this hard since some idiot threw Chairman Mao’s Little Red Book at them.

Behind him, the agonised slow-motion headshakes that have been going on since September got noticeably slower. Chuka Umunna appeared briefly to be wearily following a long baseline rally from the net side seats at Wimbledon.

David Cameron had been updating the house on his EU renegotiations, as well as explaining that that old concept of collective responsibility would be going out the window, and that come the referendum he will grant his party and his cabinet a free vote. The single biggest question of his career – whether to leave the European Union - and his cabinet won't back him.

But as with Maogate, the sheer tenacity of Team Corbyn to exploit the Government’s problems for their own disadvantage was almost to be admired.

“The Government will have a position,” Cameron said. “But it will be up to individual ministers to make up their mind.”

These, of course, are almost the identical words wearily groped for by Corbyn’s spokesperson not so very long ago, when he was forced to explain that, yes, the Shadow Foreign Secretary would indeed be arguing the opposite position to his leader over the small matter of whether to bomb Syria.

That incident, in the end, proved to be just the another crumple zone concertinaing in the slow-motion car crash that is the Labour Party in its current aggressive pursuit of electoral oblivion, but when the actual Government’s doing the same, you’d think there might be some political capital for an opposition to make.

But no. Corbyn had not only timed his 24 non-revenge non-reshuffle perfectly to undermine himself, but then came the advice session.

“Never mind how many eagles you end up with, you’ve all worked out you’ve got an albatross at the head of your party,” Cameron said, and finally a smile cracked across Hilary Benn’s lips. Five-and-a-half years after walking into 10 Downing Street, the Prime Minister has delivered his first-ever funny joke.

Later, Dennis Skinner asked Cameron a pleasingly straightforward question. “If you lose, will you resign?” He didn’t get a straightforward answer, of course. But how can you lose at anything with Corbyn around?