Paul Massara, npower CEO, said: "It's very easy for politicians to come up with simple-sounding solutions to difficult problems.
"But in reality, there are three main factors that influence prices: fixing inefficient housing stock, the investment required to replace the UK's energy infrastructure and the cost of the buying energy on the global market.
"If the Labour Party can commit to reducing policy costs on household energy bills, stopping the smart meter roll-out, preventing commodity cost increases and accept that there won't be any investment in new power stations and infrastructure, then we could freeze our prices.
"But will this make things better for Britain?"
As Ed Miliband clashes with the energy giants on prices, it is worth knowing how your expensive energy bills are actually made up.
A leading competition lawyer says an energy price freeze could leave Labour open to challenges from the courts or the European Commission.
Whether or not you approve of a state intervention into industry, there are at least two big potential obstacles for an energy price freeze.