Shadow energy secretary Caroline Flint has slammed David Cameron's energy policy annoucement, describing it is as "like something out of The Thick of It".

She accused the Prime Minister of causing "chaos" over the Government's energy policy after his announcement that firms would be forced by law to give customers the best deal.

Energy Minister John Hayes, summoned to answer questions in the Commons on the matter, did not confirm David Cameron's pledge to force firms to offer the cheapest tariff. Instead he said that the Government would legislate to "help" get the best deal.

He said a "number of options" were being considered but insisted the Energy Bill would be used to "get people lower tariffs".

Shadow energy secretary Caroline Flint, whose urgent question forced Mr Hayes to come to the Commons, said Mr Cameron's intervention had thrown the Government's policy into "confusion" and "caused chaos" in the industry.

Mr Hayes told MPs: "Following the Prime Minister's announcement yesterday I am pleased to confirm we will be bringing forward legislation to help energy consumers to get the best deal.

The Department of Energy and Climate Change appeared to have been taken by surprise by Mr Cameron's comments at Prime Minister's Questions yesterday.

Asked whether he knew what was going to be announced, Mr Hayes said: "Of course we understand what the Prime Minister was considering because we have been debating and discussing the provisions of the Energy Bill for months."