David Cameron branded Ed Miliband a Marxist today, as he adopted a full blown attack on the Labour leader's plan to freeze energy prices.
Ed Miliband started the first PMQs of the post-conference season by drily asking the prime minister whether "freezing energy prices is a good idea or a Communist plot".
Cameron answered: "There's one thing government's can't control and that's the wholesale price of gas. I know he wants to live in a Marxist universe. He needs a basic lesson in economics."
Later, the prime minister attacked Miliband for planning to cancel a drop in corporation tax and pass on the revenue to small and medium sized businesses.
"What we heard at Labour's conference was that they are going to put up taxes on Britain's most successful business. They want to fight some petty socialist campaign against big business," he said.
The prime minister also mocked shadow chancellor Ed Balls repeatedly for saying he would run the 2015 general election on his "track record".
Cameron said: "That's like the captain of the Titanic running on his safety record."
"Can I thank him for his tenacity - even though he's been wrong on every single question - that he's still in his place [following the reshuffle]? He's the great election winner for us."
The session suggests Cameron believes he can neutralise Miliband's ownership of the popular campaign on energy prices by showing the price freeze to be economically illiterate and left-wing.
It also reveals the extent to which the prime minister has become more comfortable with portraying himself as an out-and-out right winger, with repeated attacks on the BBC for its supposed left-wing slant.
The comments come after a week in which the Daily Mail found itself in hot water for suggesting Miliband's father – a Marxist academic – hated Britain.