A formal competition inquiry is needed to challenge energy firms on their gas and electricity prices, it has been claimed.
Over 50 MPs are supporting a Commons motion calling for an investigation into the activities of the Big Six energy companies namely British Gas, E. ON, EDF Energy, Npower, Scottish & Southern and Scottish Power.
Both the Conservative and Liberal Democrat leaderships are supporting the move, in addition to many Labour backbenchers, reports suggest.
John Grogan MP, who tabled the motion, said there is a lack of competition between the main suppliers, meaning consumers and businesses end up paying too much for their energy.
He added: "I do not think that the Big Six meet together and fix prices but their sheer dominance in the market and the vertical integration of power generation and retail distribution have led to a disconnect between wholesale and retail prices."
Mr Grogan said it may be necessary for the Competition Commission to "change the dynamics of the market".
Last week, David Harker, chief executive of Citizens Advice, urged consumers to compare energy prices online with a view to switching provider.
Click here to run an energy price comparison, and see if you could be paying less for your gas and electricity.