Caroline Flint, the Shadow Energy Secretary, made the assertion after two Coalition Cabinet ministers gave different responses to the Labour leader's high-profile move.
Michael Gove, the Education Secretary, made clear he took claims by the energy companies that Labour's bills freeze plan would lead to power blackouts "with a pinch of salt".
The Tory frontbencher said Mr Miliband had been absolutely right to say energy prices were too high.
Mr Gove's colleague, Eric Pickles took a tougher political line when asked about whether or not blackouts could really take place as a result of Labour's proposal. He replied: "Of course, it's a genuine threat."
He said: "We're the first Government to be able to offer to consumers the cheapest tariff, but we don't want a situation where we have a shortage of energy and the lights get turned out."
Ms Flint reacted to her opponents' views, saying: "The Tories' response to Ed Miliband's energy price freeze is unravelling. First, they said it would cause power cuts, now they're saying people shouldn't listen to scare stories from the energy companies."