EDF managing director Philippe Commaret has forecast that half of homes could be in fuel poverty in January as a result of rocketing energy prices, ahead of the increase in the price cap on bills.
Consumers will find out on Friday (26 August) how much the energy price cap will rise, with analysts expecting average annual bills to increase to more than £3,500.
"We face, despite the support that the Government has already announced, a dramatic and catastrophic winter for our customers," Commaret told BBC Radio 4's Today programme.
"In fact, in January half of the UK households might be in fuel poverty. That's the reason why we want to take actions in order to do everything we can do in order to help our customers.
"So, we are announcing today that we are going to launch a campaign in order to reach hundreds of thousands of our customers to provide them further support to help them cut their costs, but also make sure that they are accessing all the available support that is available for them."
The war in Ukraine and the economic isolation of gas-producing Russia, combined with surging energy demand following the easing of coronavirus restrictions around the world, has driven up prices and caused uncertainty in international supply.
Regulator Ofgem will announce the new level of the price cap, with energy industry consultants Cornwall Insight warning that households will face an 80 percent rise in bills going into the winter period.
Energy prices are tipped to hit £3,554 from October, then rise to £4,650 from January. So between October and April – which includes the coldest months of the year – the average household will pay an equivalent £4,102 per year for their gas and electricity.
It would be a massive jump from today's £1,971, which is already a record, and much higher than the £1,138 seen last winter.
No immediate extra help will be announced by Boris Johnson's Government, with major financial decisions being postponed until either Liz Truss or Rishi Sunak is in No 10 following the Tory leadership contest, which is set to conclude in under two weeks.
Sunak has pledged to remove VAT from energy bills, while Truss has promised to cut green levies.
Commaret said: "I think that all ideas in order to keep the bills for customers flat are really important and have all to be considered.
"There is not only one lever to be pulled but all levers have to be pulled right now because we face a catastrophic winter."
Downing Street has insisted there is no need for consumers to panic.
A Government spokesperson said: "Households, businesses and industry can be confident that the UK's secure and diverse energy supplies will provide the electricity and gas they need."