Figures revealed yesterday that more than 3,000 people died of cold-related ailments last week, with campaigners putting the increase down to people being unable to afford to heat their homes.

Campaigners linked a spike in weekly winter death figures to speculation that the total number could soar as high as 40,000 this year and warned that most will be pensioners.

They say the deaths are a direct result of rip-off energy companies’ profiteering and Regulator Ofgem’s refusal to take action against the “big six” energy firms.

Energy campaign group Fuel Poverty Action says the scandal must end and is calling for public ownership of Britain’s energy supply industry.

The big six have made belated and tokenistic cuts to bills but this is seen as a drop in the ocean in comparison to their huge profits, which hit £2.6 billion in 2013-14.

The shocking figures came after a Which? study revealed that gas and electricity bills should have been reduced by £145 last year in response to plummeting wholesale prices.

Ofgem has instead insulted those struggling to pay their exorbitant bills, responding to growing fuel poverty by urging households to eat more packed lunches.

In response, Fuel Poverty Action staged a “packed lunch protest” outside Ofgem’s London headquarters yesterday.

Clare Walton of Fuel Poverty Action said: “Ofgem is dishing out insulting and patronising advice and is telling poor people to change their behaviour, when it’s the big six who need to change their behaviour.

“We’re protesting to highlight the absurdity of the situation — thousands of people are dying, we know the bills have been to rigged to benefit the big six and yet somehow it’s lunchtime meal deals that are to blame.

“We are utterly appalled that the Big Six’s profit margins are growing off the backs of their refusal to cut their bills in line with wholesale prices.

“Combined with the news that bills could have been £145 cheaper last year and Ofgem’s only intervention being patronising people to stop buying lunch, it is abundantly clear that our private energy system simply isn’t working.”

The group is demanding an energy bill of rights to protect consumers.

Energy companies have the right to forcibly enter people’s homes to install pre-payment meters which cut off gas and electricity supplies if payment is not made.

More than 10 million have been installed.