Four million of Britain’s poorest homes may have to find another £80 a year for energy from April.
Power experts believe industry regulator Ofgem will raise the annual price cap for those on pre-payment meters from an average of £1,070 to £1,151.
Such meters tend to be in households already struggling to make ends meet.
And the £81 increase, predicted by leading energy consultants Cornwall Insight, would virtually wipe out a £95 annual saving announced in October.
Robert Buckley, of Cornwall Insight, said rises are driven by higher wholesale energy costs which, unless they fall, may see the cap rise by another £40 or £50 next winter.
Adam Scorer, of the charity National Energy Action, said other customers can avoid higher bills by switching supplier or tariffs.
But he said: “PPMs users are often trapped, with no options and just have to take the hit or keep the heating and power off. This will hit millions of pre-payment customers who are already facing a tough winter. They should be better protected from price rises.”
Cornwall believes Ofgem will raise the cap by £66 for 11 million customers on standard tariffs, who also face a £21 a year charge to cover others missing repayments due to the Covid-19 crisis.
Ofgem declined to comment.
