David Cameron has insisted that the decision to freeze fuel duty was not a Government U-turn as Labour branded the move "another case of panic at the pumps".
Ed Miliband claimed stopping the 3p increase planned for August was proof that "plan A was not working". But the Prime Minister insisted the coalition was "defusing Labour's tax bombshell".
He told MPs: "The fuel duty increase was a Labour tax rise. It cannot be a U-turn to get rid of a Labour tax increase. They put in place 12 increases on fuel duty in government. They left behind six increases in fuel duty and I'm proud of the fact we are dealing with them."
Government ministers were not told in advance of Chancellor George Osborne's £550 million decision to suspend the 3p hike in fuel duty, Downing Street indicated earlier.
Mocking the Prime Minister, the Labour leader questioned why he had forgotten to tell the rest of the Cabinet and the party's backbenchers about the plan.
"So it was all part of a seamless political strategy?" he said.
Speculation that the Chancellor might not have warned his colleagues was sparked when junior Treasury minister Chloe Smith refused repeatedly to tell interviewer Jeremy Paxman when she had been told about the decision.
Mr Osborne was branded a "coward" by a Conservative backbencher for sending Ms Smith on to BBC2's Newsnight to defend the policy shift.
Mid-Bedfordshire MP Nadine Dorries - a vocal critic of the Tory leadership - said in a series of messages on Twitter: "If Osborne sent Chloe on re scrapping 3p he is a coward as well as arrogant.
"Newsnight last night would have been a tough gig for a minister with years of experience - Chloe is a good egg and didn't deserve that. The request for Newsnight should have been refused or given a pre-recorded interview. Paxman was doing his job, Osborne wasn't."