WITH normal service resumed after the assault course that is the party conference season, birthday boy Dave (he's 47) did his level best to leave the impression that Red Ed was, in fact, Marxist Ed.

After the Daily Mail's hateful row about the late Ralph Miliband, one might have thought the Prime Minister would have soft-pedalled a bit on the whole Marxism front, but none of it.

To be fair, the M-word was first alluded to by the chief comrade himself, who tried to underscore what he believes is a vote winner: his energy price freeze.

The Labour leader pointed out how the PM had referred to the policy positively, saying it had "struck a chord" with the public while the Chancellor had suggested it had come straight from the pages of Das Kapital. So, Mr M asked, was freezing energy prices a good idea or a Communist plot?

As laughter erupted, Blue Dave declared: "I'll leave the Communist plots to him."

Red Ed accused him of "floundering around" on the energy freeze policy, while the PM insisted that his opposite number had to realise governments did not control wholesale oil and gas prices, noting: "I know he'd like to live in some kind of Marxist universe where you can control all these things but he needs a basic lesson in economics."

But perhaps the PM needs a basic lesson in Government policy after coming something of a cropper on the Tories' marriage tax break plan.

Early on in exchanges, Blue Dave declared lustily the policy was "not about the money; it's about the message".

But then the PM insisted "all married couples paying basic rate tax" would benefit from the tax break.

The two Eds looked quizzically at each other. Er, no it won't. It will be available only to those basic rate taxpayers whose partners do not work or earn less than the income tax threshold of around £10,000; estimated to be less than a third of all married couples.

Incensed, the Shadow Chancellor took PMQs to extra time with a Point of Order, urging Blue Dave to correct himself. After much goading from the comrades, the Tory chief slowly rose and, very slightly, changed his wording to how the tax break would be "available to every basic rate taxpayer".

Outside, the Prime Minister's aides looked nervously at their shoes as they tried to explain(unsuccessfully) the gaffe away - but there is not a lot that you can do when even the head of government can't get the policy right.