New research has revealed the UK's 'Big Six' energy suppliers saw profits sky-rocket by more than 70% in the three years up to 2012.
Compiled by Labour, the data shows the profits of firms including Eon, EDF and SSE soared by a staggering 73% to £3.74bn in 2012 - compared to a figure of £2.16bn back in 2009.
The news is certain to once again start a debate over the issue of high energy prices when many struggle to make ends meet.
Shadow energy secretary, Caroline Flint, was quick to point the finger at David Cameron, claiming the PM was out of touch - with many households and small businesses struggling to find enough to pay their energy bills each month.
She said: "His failure to reform Britain's broken energy market is leaving hard-pressed bill-payers massively out-of-pocket."
Ofgem figures show the average domestic fuel bill has risen by over £300 in the last three years - up to £1,420 a year compared to figures of £1,105 in May 2010.
Energy UK chief executive, Angela Knight, defended the energy firm's her industry group represents however, claiming the Labour review was unnecessarily bashing an industry that pays billions of pounds in tax each year while providing the power needed to keep the country running, as well as employing more than 600,000 staff.
She said: "If a company is to stay in business, it has to make a profit. And the more a company has to invest then it has to make more profit to do so.
"What is actually needed is a clear, sensible and coherent debate on what people want, how much wind power and how much gas, nuclear and coal is needed, what capacity is required and, critically, how much people are prepared to pay for it all."
Despite fingers being pointed at them due to high energy bills, many of the 'Big Six' suppliers are participating in the government's Green Deal.
Under the scheme they offer loans or cashback incentives on energy improvement measures such as the fitting of a new boiler or loft and wall insulation, working under the principle that the customer will only have to pay back the loan after energy savings outweigh the cost of the work done.
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