Liberal Democrat leader Nick Clegg said he will host a meeting of energy industry leaders to discuss "radical alternatives" aimed at helping families struggling with high fuel bills.
He said the situation whereby consumers were charged more for the first units of energy used and less as they used more should be reversed.
It meant pensioners were effectively paying more for their heating than millionaires in luxury mansions, a situation he blasted as "scandalous".
In an interview on Sky News, Mr Clegg said millions of people were still in fuel poverty under Labour.
He said: "For people this winter there is a real dilemma, we have had three weeks of hard frost up and down the country... people are having to choose between heating and eating. We have got to take radical action, come up with radical alternatives.
"At the moment you pay more for the first bits of energy you use - this is crazy. The more you heat your home the less you pay, it should be the reverse."
He added: "At the moment we have a scandalous situation where a pensioner has to pay more to heat a single room in her home than a millionaire who heats a five-storey mansion. That needs to be changed so you pay less at the beginning, more later, so the more you use, the more you pay."
Mr Clegg said his party had been consistently "ahead of the game" on the economy, the environment and civil liberties.
He added: "Again and again we have been coming up with practical solutions to the very dilemmas that people face.
He said he wanted to "significantly reduce" the tax burden for low and middle earners, calling for a "re-balancing" of the taxation system. Public spending should be prioritised better such as elderly care, pensions and schools. He added: "If we have headroom to deliver further net tax cuts we will do so."
