Over one million households went into debt in the past year, and over 5m homes currently owe money, uSwitch said.
While price cuts last spring caused the average debt to fall £8 to £123, this year’s increased winter prices and the bitterly cold spring have brought the total energy debt to £637m, or £159m more than last year.
Forty-one per cent of households say they owe more now than they did a year ago, while just nine per cent owe less.
Though 22 per cent intend to pay their debt with a lump sum, 22 per cent intend to ignore their arrears and hope they naturally diminish.
Forty-five per cent plan to increase their regular direct debit payment and eight per cent hope to agree a repayment plan with their supplier.
Ann Robinson, director of consumer policy at uSwitch.com, said that the figures were “a clear indication of the pressure people are coming under just to meet the cost of their basic bills”.
Meanwhile, politicians on the energy and climate change select committee have called for voters to submit questions for the larger energy providers on Twitter, ahead of an evidence session next week.
MPs will put responses to senior figures from firms including British Gas, EDF, Scottish Power and E.ON on 16 April.
Also attending will be an executive from SSE, which was slapped with a record Ofgem fine of £10.5m last week for mis-selling gas and electricity over the phone and through doorstep selling.