Millions of British Gas customers have been urged to consider switching suppliers for a better deal after the energy giant announced record bill increases.
The company said gas bills would soar by 12.4 per cent and electricity by 9.4 per cent to compensate for higher wholesale prices.
Yesterday's rise is the second of the year by British Gas, following a 5.9 per cent increase in January.
Critics attacked the scale of the increases and warned vulnerable customers would be hit hard.
The increases mean gas customers will see their bills rocket by almost one-fifth in less than a year.
Analysts say the latest increase, due to take effect from September 20th, will add £99 stelring to the annual bill for a family of four who buy both their gas and electricity from British Gas.
British Gas said the increases, its highest since the market was opened to competition in the mid 1990s, were due to record wholesale gas prices.
Mr Mark Clare, managing director of British Gas, said: "Depletion of North and Irish Sea gas reserves, the UK's consequent need to import larger volumes of gas and high oil prices are pushing up wholesale prices.
"The era of cheap UK energy is over but we have confidence that the investments we are now making in future energy supplies will, in the long term, put downward pressure on commodity costs for the benefit of all our customers."
The company said it understood some people could be hurt by the increases and has pledged £10 million to set-up a fund to assist vulnerable customers who need help paying their bills.