New research has shown energy companies have pushed up power bills by as much as £250 per household in the UK.
The information, unearthed by shadow energy secretary Caroline Flint, revealed industry mark ups have gone up 39% in the case of electricity and 69% in the case of gas in the last ten years.
For the average household the mark up has led to a £91 increase on domestic electricity bills and around £165 on a typical gas bill.
Shadow energy secretary, Caroline Flint, put the blame firmly at the doors of energy company fatcats, blaming them for driving up power bills.
She said: "They always blame rising global energy prices for putting up people's bills, but these figures show they've been increasing their profits on the back of spiralling energy bills for hard-pressed households.
"If they won't treat customers fairly, the public deserve tough action. Labour would create a tough new energy watchdog with the power to force firms to cut prices when the cost of energy falls."
However, a spokeswoman for the industry body, Energy UK, argued the mark up figures were not such a simply case of black and white.
The spokeswoman said: "The percentage difference is actually less now. And the proportion of bills made up of electricity and gas is falling. Other elements include network charges and the rising cost of government schemes."
Many energy companies are participating in the government's Green Deal, in essence a loan for customers to fit items such as energy-efficient boilers or wall insulation into their homes in order to make it greener and cut down the amount paid on energy bills.
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