A cap on household energy bills will be included in the Conservative manifesto, a cabinet minister has said.
The party's plans could reportedly cut gas and electricity costs by £100 a year for 17 million families.
Work and Pensions Secretary Damian Green told ITV they were different from a Labour promise at the 2015 general election to freeze energy prices.
He said the Tory plan would be "more flexible" and consumers would benefit if wholesale prices fell.
The Sunday Times reported that the Tories would cap bills for seven out of 10 households paying standard variable tariffs, which are often criticised as bad deals for consumers by industry watchdogs.
It follows the introduction of a cap for households using pre-payment meters early this month, after the Competition and Markets Authority released a report saying customers were overpaying by £1.4bn.
Mr Green told the Peston on Sunday programme: "There will be a lot about energy policy in the manifesto [and] obviously there will be more detail.
"But... I think that people feel that some of the big energy companies have taken advantage of them with the tariffs they have got."
In 2013, former leader of the Labour Party Ed Miliband said he would freeze gas and electricity bills for every home and business in the UK for 20 months if he won the 2015 general election.
He said firms had been overcharging "for too long" and it was time to "reset" the energy market.
At the time, the Conservatives accused him of a "sleight of hand", saying people would ultimately have to "pay more for their electricity" under the plans.
Mr Green said the new Tory promise on energy was different.
"The difference is that we would have [energy regulator] Ofgem setting the limits," he said. "So it would be a cap, it would be more flexible, it would be able to reflect market conditions [and] the market would still have an influence.
"That would mean in practical terms that if the oil price fell again, then consumers would benefit, which they wouldn't have done under Ed Miliband's proposal."