FIRST it was Shakespeare, now it is the Beatles. PMQs is literally becoming a festival of quotes.

This week’s unmissable opportunity for Dave to poke fun at Jezza came over the Labour leader’s flagging up of the possibility that Britain could have nuclear submarines but, er, without the nukes.

The subject was broached by Karl McCartney, the Conservative champion for Lincoln, who asked his noble leader: “Do you agree with me that our nuclear deterrent only works against our nation's enemies if our nuclear submarines are actually equipped with nuclear missiles?

"And that those such as the Leader of the Opposition, who do not believe this, have a defence policy inspired by The Beatles' Yellow Submarine and shows that while the members opposite may Twist And Shout, their current leader certainly needs Help."

As Labour eyes rolled, Tory voices chuckled with glee.

Now, never one to miss an opportunity to rib the hairy Leftie, there was a strong suspicion from Her Majesty’s Press that Mr McCartney had been handed the question to enable Dave to deliver a Beatles punchline.

So, after congratulating his Tory chum on his "ingenious question", the PM said: "There is a comic element to sending submarines to sea without missiles in but, in fact, it is absolutely serious because the deterrent has been, on a cross-party basis, an absolutely key part of our defence and making sure we have got the ultimate insurance policy, which we support on this side and we should vote on in this House.”

Then, puffing out the prime ministerial chest, Dave added: "All I can say when it comes to Beatles songs, I suspect that the Leader of the Opposition prefers Back in the USSR."

Earlier, Jezza declined to accept the PM’s offer of welcoming the fall in unemployment and the record high on employment and sought instead to resurrect the people’s PMQs with references to Liam and Vicky and questions about the abolition of student maintenance grants.

After brushing aside the chief comrade’s focus on hard-up students, Dave could not help alighting on Labour’s post-mortem this week about why it had lost the General Election.

The Tory toff leant against the dispatch box and chatted to his chums, saying: “I have to say that this week has all been of a piece with a retreat by the Labour Party into the past,” pointing to Jezza’s suggestion of bringing back unilateral nuclear disarmament, secondary picketing and flying pickets.

“It is extraordinary,” the PM told MPs, “a party, that spent so long trying to cast off the image of being in favour of these appalling industrial practices…is backing a leader, who would take us right back to the 1970s.”

Time, as Dave once said, to fire up the Quattro.