Theresa May's proposed cap to tackle "rip off" gas and electricity prices is nothing like the plan suggested by Ed Miliband in 2013 because "the real thing is always better than the imitation", the former Labour leader has said.
The Prime Minister said her proposal could save families up to £100 a year after she condemned a market that sees customers of the Big Six suppliers paying £1.4 billion more than they would in a "truly competitive market".
The pledge when announced by Labour proved very popular in 2013 and was a central part of the party's 2015 General Election manifesto.
Speaking exclusively to ITV News Mr Miliband sought to distance his former pledge from that put forward by the Prime Minister: "I think if they were going to copy my idea Theresa May should have done a much better job of it than she's done.
"Looking at the detail and the fine print, they're not guaranteeing that there won't be a rise in prices - as we did - they're saying somebody else has got to make that judgement, so she certainly can't be promising money off bills or even that prices won't carry on going up."
The Tory's proposal differs from Labour's as it suggests that Ofgem would set the cap, not politicians.
Mrs May echoed the Labour candidate for Doncaster North, stressing the difference between the pledges made by Labour and the Conservatives: "Ed Miliband didn't suggest a cap on energy prices," she said from ITV News Political Correspondent Emily Morgan.
"Ed Miliband suggested a freeze on energy prices that would have frozen them so that people paying above the odds would have continued to pay above the odds and crucially the prices couldn't have gone down. Under our cap the prices will be able to go down," Mrs May added.
Mr Miliband continued that the "real thing is always better than the imitation" in reference to his proposal.
Mr Miliband also branded the pledge a a "price con, not a price cap," since "Theresa May admitted she can't guarantee that energy bills won't keep on rising".
Mr Miliband stressed that his pledge was very different from the Prime Minister's: "We had a proper worked-out policy which could actually bring the much-needed release that people wanted to see, and I think lots of people will be asking today: 'Theresa May, what about all of that money that we've paid over with rising prices year after year, when the Conservative Party defended a broken energy market?'
"Now she comes along today and she'd not actually going to give the guarantee that people actually want to see."
Mr Miliband said that his "fear" was that the Conservative's proposal would not "guarantee that bills won't keep going up".
The 47-year-old continued that "rising energy bills are a big issue" and "real action needs to be taken.
"The energy companies are essentially ripping off the consumer.
"You've got to bring real immediate relief - which our policy would have done - but also reform the energy market so they can't keep doing that, and I don't see the Conservatives doing that."
Mr Miliband continued he would like to see the "regulator play more of a role to bring bills down."