British Gas is putting its prices up by an average of 18pc or £121 for gas and 16pc or £71 for electricity from August 18.
It means that the average household bill for a dual fuel British Gas customer will now go up from £1,096 to £1,288 – an increase of £192 or 17.5pc.
Phil Bentley, managing director British Gas, said its bills were being driven higher by the fact that the company buys 50pc of its gas on the international wholesale market.
He said: "We are buying in a global energy market and have to pay the market rate. Rising wholesale costs is an issue facing all energy suppliers."
Ann Robinson, Director of Consumer Policy at uSwitch.com, said: “We are straying into deeply worrying ‘double price hike’ territory.
"The impact on family budgets will be huge, but it will be particularly hard on those living on fixed incomes and I would urge both suppliers and the Government to start thinking now of how they can provide some support. It may seem a long way ahead, but winter will be coming too quickly for those who cannot afford their fuel bills." -By Paul Farrow，08 Jul 2011