Warning over energy price rises

Mr Wicks put the blame for domestic energy price hikes on massive increases in the cost of oil, gas and coal on global markets.

His comments came after reports that unnamed industry sources believe household energy bills could increase by as much as 40% this winter.

Mr Wicks did not confirm the reported rises, which it is claimed could add £400 to a family's bills.

Asked if he recognised the figure, he said in an interview: "There are estimates and guesstimates and guesses. Let's see what happens."

Meanwhile, British Gas parent Centrica said it was on track to make around £1.9 billion this year as millions of households brace themselves for price hikes.

The performance will be below last year's operating profits of £2.2 billion, as it warned in May that soaring wholesale gas costs would lead to "materially lower" profits.

But the firm is almost certain to hit 15.9 million customers with higher bills later this year as it takes the "necessary action" to rebuild margins at its residential business.

The company, like the rest of the UK's "big six" suppliers, has been struggling with big rises in the cost of wholesale gas.

A year ago British Gas made profits of £533 million from the first six months of 2007 delays in passing on cheaper costs to customers, but some analysts have said the residential business could make a first-half loss this time.