The "Big Six" energy giants are under pressure to pass on every penny of fuel savings expected to be announced by ministers next week.

The Coalition Government has announced that it plans to roll back some of the so-called green levies on household bills.

The move could save up to £50 a year for the average home.

But there are growing demands for energy companies to make sure that the savings are passed on to consumers.

Already a number have said that they will ensure customers receive the full benefit of the cut.

The roll back is expected to be announced by the Chancellor George Osborne in his Autumn Statement next week.

The move is the product of tense negotiations with the Liberal Democrats who oppose reductions to taxes which help poorer consumers.

Downing Street yesterday denied that ministers were placing pressure on the Big Six to hold prices until the general election.

But No 10 did intimate that it wanted customers to benefit from the full effect of price reductions.

Asked if he expected the full reduction to be passed on to consumers, David Cameron's official spokesman said: "The whole point of this is to help households and families".

The Coalition is struggling to get on the front foot over the rising energy costs ahead of the cold winter weather.

Labour leader Ed Miliband has led the debate on the issue of rising energy prices for weeks, since he announced plans for a price freeze in his party conference speech in Brighton on September 23. Yesterday he said Mr Cameron was a "weak and flailing Prime Minister".

The Prime Minister said his plans were a "world away from making a vague promise about something you might do in 20 months' time with no idea about how you are going to do it."

He added: "That is a con."

"What we are dealing with is real policy that can make a real difference."