EDF Energy has announced it will cut its gas bills by 5% from 7 February, offering cash-strapped families a glimmer of hope amid soaring household bills.
The move, announced on Wednesday, came as a report by Which?said consumers may be missing out on millions of unclaimed compensation from the big six energy companies due to faulty meters or inaccurate bills.
EDF, which increased its gas bill by 15.4% in November, after a rise of 6.5% in February, said it was the last of the major suppliers to increase its prices last autumn and is the first to announce a cut.
Chief executive Vincent de Rivaz said: "What customers want more than anything else is fair, clear and transparent prices.
"We know they want action rather than words. That is why we are the first major supplier to announce a cut and were the last to increase prices."
The move follows speculation over the weekend that British Gas owner Centrica was considering a 10% reduction in households energy bills.
Wednesday's report by Which? showed that EDF finished second bottom in a table of the biggest six energy suppliers. Only 43% of its customers said they were satisfied with the company's service or likely to recommend it to others.
The result comes after the introduction of a new billing system led to a surge in complaints from customers.
EDF said an average dual fuel bill customer with typical consumption paying by monthly direct debit will face a bill of £1,137 a year, compared with the current figure of £1,218 a year for British Gas.
It also increased prices in 2008, by 12.9% in January and 22% in July, and in 2006 it brought bills up by 14.7% in February and 19% in July.
Previous price cuts took place in July 2007, by 10.2%, and March 2010, when they went down by 4%.
Commenting on today's move, Which? executive director Richard Lloyd said: "This gas price cut will be welcome news for millions of consumers with already squeezed household budgets. But it follows a hike of 15% last November.
"Now the pressure is on for the rest of the major suppliers to follow suit. But as our survey today shows, there remain huge problems with customer service in energy as well as high prices."