Thousands of Bradford households have received a fresh blow to their finances after the UK's largest energy supplier announced double-digit price hikes.

Centrica is to increase gas and electricity tariffs by an average 15 per cent with immediate effect - a move impacting an estimated 13 million British Gas customers.

In doing so yesterday, the provider became the third big energy supplier this year to raise standard tariff prices, following rivals EDF and npower, as the industry passes on soaring wholesale energy and distribution costs.

The announcement will take the average annual dual fuel bill for a British Gas customer to £1,055, up £143. Those paying by direct debit will see bills go up an average of £131 to £968.

The electricity price rises are subject to regional variation of between 19-12 per cent.

This is because British Gas is charged varying amounts by power networks to distribute its electricity.

Centrica, which cut its prices twice last year, said it was unable to carry the "burden" of the rising wholesale energy costs, as much as 61 per cent year on year, and that its residential arm would make a loss this year unless the hikes came into force. But the UK's second supplier Scottish & Southern Energy, which has 8.5 million customers, said it would hold its bills down until the end of March at least.

British Gas said 2.4 million customers on fixed-term tariffs lasting up to 2010 would be unaffected by rises, and that it would also delay them for another 340,000 "vulnerable" customers until the end of winter.

Consumer group energywatch said it was "sick and tired" of hearing about the gas and electricity companies' justifications for price rises.

It is the latest blow for households after a year in which petrol, mortgage interest payments and food prices have all risen sharply.

Energywatch chief executive, Allan Asher, said: "This increase piles on even more agony for consumers who are facing a salvo of mid-winter double-digit energy price rises.

"Energy price rises are coming in thick and fast and like every other consumer I'm sick and tired of hearing energy companies try to justify the latest bout of pain they are inflicting on their customers. It is obvious that this market is not delivering good value to consumers.

"The reasons are well known and explain why energywatch has been calling on the Government to call in the Competition Commission to put this market under the microscope."

British Gas made losses of £143 million in 2006 but returned to the black with profits of £533 million in the first half of 2007, helped by cheaper wholesale gas costs.

Gordon Lishman, director general of Age Concern, spoke of his disappointment that the rises were being imposed now.

He said: "We're really disappointed that, despite their very healthy profits, the big energy firms don't think they can afford to put off these increases until after the winter quarter.

"This is when the poorest pensioners worry most about their bills."

Announcing the price rise, British Gas managing director, Phil Bentley, said: "As the UK's biggest buyer of gas, we want lower gas prices.

"However, lower availability of supplies from both the UK and the Continent, coupled with higher global oil prices, have forced up wholesale prices.

"We can't absorb the burden of these higher energy prices and the costs of delivering a cleaner environment."