A bereaved man’s energy bills increased by 55pc following the death of his wife, after Scottish Power, his supplier, cancelled his fixed-rate deal.

Simon Moores, 58, from Liverpool, lost his wife, Sarah, in February. When he contacted his supplier to move the account from his wife’s name to his, Scottish Power raised his bill from £97 to £150 a month. The company said it would close the account, which had a fix in place until July, and open a new one at its more expensive standard variable tariff.

“When I asked why, they said, ‘That’s just our procedure,’” Mr Moores said. “There was nothing I could do about it.”

After Telegraph Money contacted Scottish Power, the Big Six energy company, which supplies one in 10 British homes, reinstated Mr Moores’s fixed rate and credited his account with £75.

Millions of people face a huge jump in energy bills next month, when the energy price cap, which limits how much suppliers can charge on default tariffs, will rise from £1,277 to £1,971 a year – an increase of 54pc. Customers on fixed-rate deals will be protected until the end of their term, but will then have no choice but to pay more, as there are no fixed deals that are cheaper than the energy price cap.

The average fix costs £3,444 a year, a record high. The 10 cheapest cost an average of £3,015.45 per year, according to Uswitch, a price comparison website. The best deal is SSE’s two-year Fix and Protect v4 tariff, which charges £2,789.99 a year.