The big six energy firms could be in for a challenge in 2013 as smaller independent companies are now offering cheaper deals.
Eon, NPower, British Gas, SSE, EDF and ScottishPower currently control 98 per cent of the UK domestic energy market but four of the five cheapest plans come from independent businesses.
And Labour MP for Glasgow North West John Robertson says it is "absolutely ridiculous" that small firms can afford to undercut the big six and is encouraging the government to "take ownership" of the problem and reform the energy market.
He says the most vulnerable are the "hardest hit" and called for a windfall tax for those making "excessive profits", whilst urging the public to compare deals.
A recent survey revealed that just 52 per cent of people would consider signing up with a smaller energy supplier, which suggests many are worried about the consequences of switching from the big six.
As many as 35 per cent of respondents admitted being concerned that a smaller supplier might go out of business, and 28 per cent said they would be worried they would have their supply cut off if something went wrong.