“Rising fuel bills are bad news for poorer customers. As prices go up, heating may be turned down well before it is warm enough to do so.

“The Government’s failure to protect and support those most vulnerable from sinking deeper into fuel poverty is complete negligence. How many more pensioners must languish in fuel poverty before we see action?

“Help The Aged welcomes the renewed commitment from the Government to meet its target to end fuel poverty in the UK by 2018.

“But the Government’s recent admission, that its target to eradicate fuel poverty in vulnerable households by 2010 will be significantly missed, is appalling.”

About 4.5million people live in fuel poverty – which is measured when more than 10 per cent of their disposable income goes on energy.

That figure is up from four million last year. Critics last night said the Government should have done something about the problem much sooner.

Allan Asher, chief executive of customer watchdog Energywatch, said: “Companies have been abusing consumers for far too long while the Government has stuck its head in the sand.

“Companies are profiteering from the poor and it’s outrageous and immoral.”

Mr Asher also said tens of thousands of people die every winter from hypothermia and respiratory diseases because they cannot afford adequate heating.

Lesley Davis, the chairman of the Right To Fuel campaign, said the profits of energy companies had risen by £2.3billion in the past three years.

Five of the “Big Six” suppliers – E.ON, npower, British Gas, EDF Energy, ScottishPower and Scottish And Southern Energy – have increased prices since the start of January. Some prices rose by as much as 16 per cent.

The average annual total gas and electricity bill now stands at more than £1,000.

Chancellor Alistair Darling is expected to mention fuel poverty in his first Budget on March 12.

Although he is not expected to announce a windfall tax outright, officials say he is keeping the move as a last resort.

But a scheme to tackle the problem is anticipated. Last night a Treasury spokesman said: “We won’t speculate ahead of next week’s Budget statement.”

The energy companies say they are already helping the poor with a series of reduced tariffs and assistance with home insulation.

Some experts believe they are likely to regard the threat of a windfall tax as a bluff.

The levy would be unpopular with business at a time when relations are already strained thanks to reforms to capital gains tax and plans to impose a “non doms” levy on wealthy foreigners.