Gas prices are likely to soar, then remain high, it is reported.
Channel Four News said it had seen an internal report for the company Centrica which suggested gas prices could rise by 70%.
Jake Ulrich, managing director of Centrica Energy, told the programme: "I think it is going to hit people hard."
He admitted that gas price rises were likely to lead to a "potentially significant" rise in the number of people in fuel poverty.
And he predicted people would have to change their habits to deal with higher prices.
"I do think we will see people change their behaviour, I think people will use less energy and I hate to go back to the Jimmy Carter days in the US but maybe it's two jumpers instead of one.
"I think people will change the temperature they keep the house, they'll be more cognisant of energy waste, they'll buy better appliances."
Gas prices are likely to remain high in the foreseeable future, he said. "The pressure is going to be upwards on prices for some time."
And he added: "We're part of a world economy and I don't think we can rely on UK production or cheap gas, cheap energy of any sort any more.
"I think it's a reality not only in the UK but in Western Europe and North America - energy is going to become relatively much more expensive in the future."
