Other energy firms are expected to follow suit.

EDF blamed record wholesale energy costs for the increases, which came into effect immediately. It is the second time it has raised prices this year.

The French firm, one of Britain's biggest energy suppliers with 5.1 million customers, said typical dual-fuel bills would increase by £3.97 a week – or just over £200 a year.

The announcement came a day after Scottish & Southern warned customers it was likely to increase energy prices.

An independent report last week commissioned by Centrica, owner of British Gas, warned that prices could rise by 70 per cent.

British Gas last night said its pricing had not changed but analysts and industry sources fear big increases in household energy bills from all suppliers over the next few months.

Eva Eisenschimmel, chief operating officer of EDF Energy customers branch, said: "Record world oil prices have continued to drive up wholesale gas prices. Alongside unprecedented rises in wholesale coal and electricity costs, this has impacted hugely on the cost of supplying energy to our customers."

The company said wholesale energy prices had increased by 70 per cent for coal, 63 per cent for gas and 47 per cent for electricity since it last increased its prices in January.

Ms Eisenschimmel said: "We have been absorbing some of these costs in recent months, but we now have to pass on some of the resulting rise in wholesale costs to our customers.

"While the rise in wholesale prices is out of our control, we have been doing everything possible to keep costs in check."

Adam Scorer, director of campaigns for watchdog Energywatch, said: "Consumers have been bracing themselves for price hikes but the scale of these rises will be a hammer blow to many.

"The blame is being laid squarely on rising oil prices and the knock-on effect it has on wholesale gas prices. The indexation of the price of these two separate commodities must be explored, and if the link is found to be artificial and unfair, action needs to be taken to see what remedies can be implemented.

"If, as is likely, EDF's fellow energy suppliers follow suit then fuel poverty will be visiting more than one million new households and the number of pensioners and families in extreme fuel poverty will soar."

Age Concern director-general Gordon Lishman said: "Yet more huge hikes in energy prices will horrify many pensioners who are already struggling to pay rapidly rising household bills.

"The help being offered to the poorest and most vulnerable energy customers by the government and energy companies is woefully inadequate."

Tim Wolfenden, head of home services at price comparison website uSwitch.com, said:

"This is not going to be a unilateral move. Other suppliers are sure to follow suit."

FACT BOX

THE UK edged closer to recession yesterday after official figures showed growth fell to just 0.2 per cent between April and June.

The damage was done by a house-building slump as the economy grew at its slowest pace since the beginning of 2005, according to estimates by the Office for National Statistics (ONS).

Paul Dales, UK economist at Capital Economics, said the figures fuelled expectations that the UK faces a period of recession – defined by two consecutive quarters of negative growth.

"The economy has weakened dramatically even before the full impact of the credit squeeze and housing downturn has been felt. An outright recession is now our central scenario," he said.

Business leaders at the British Chambers of Commerce also warned of a "dramatic worsening in economic prospects".

"The position is likely to deteriorate in the second half of the year. We now expect zero or negative growth in the next two or three quarters," economic adviser David Kern added.

But the Bank of England is unlikely to come to the rescue with rate cuts in the near future because surging fuel and food costs have pushed inflation to almost double its 2 per cent target.