One in three people are concerned about paying their energy bills this winter, while more than half say they are struggling with household finances, a survey has found.
The poll, taken before British Gas announced this week that it is to hike electricity prices by 12.5% for 3.1 million customers, found 32% of bill payers are worried about how they will meet their energy costs when the colder months set in.
Some 55% are already struggling to pay their household bills, but 29% of energycustomers have never switched provider, uSwitch found.
British Gas was the last of the Big Six energy providers to increase prices after it promised in December last year to freeze tariffs until August, with its rivals moving to raise bills at the start of the year.
Claire Osborne, uSwitch.com energy spokeswoman, said: "It's appalling that a third of Britain's households are already worrying about how they will be able to afford to keep warm this winter, especially when half of them are already struggling with their household finances.
"To make matters even worse, the latest price hike from British Gas will hit three million more energy customers just as they start to think about putting the central heating on.
"Whether you own your own home or rent, and whatever part of the country you live in, all energy customers have the right to choose the tariff that's best for them rather than accepting whatever price their supplier imposes."
More than half of consumers (53%) say they have turned down the thermostat or worn more layers (51%) to avoid putting on the heating, while 33% say they they have not turned the heating on at all, even when it is cold.
Bill payers who have stayed with their supplier energy for more than two years without actively choosing a tariff, or have never switched at all, are likely to be on the most expensive Standard Variable Tariff, which has an average current price among the Big Six of £1,138, £304 more expensive than the cheapest deal currently on the market.
Among those who have never switched, 33% said they did not think they would save much money, 19% thought all suppliers were the same and 17% found the switching process too complicated.