The Conservatives have said nuclear power should be used only as "a last resort" to supply the UK with energy.
Tony Blair has said older nuclear plants will have to be replaced
Their Energy Review's interim findings say there should be a "level playing field" for environmentally-friendly sources and other means of power.
Labour argued the Conservatives' proposals would "set renewable development back by a generation".
Meanwhile Tory leader David Cameron used a speech to say councils had a key role in ensuring a low carbon future.
He argued that, in a post-Cold War world, global warming represents the greatest long-term threat to the planet.
Tony Blair has said that nuclear power is back on the agenda as a result of fears over the security of energy supplies to the UK, rising prices and also climate change.
But at the weekend shadow trade secretary Alan Duncan said his party wanted to "explore every conceivable method of generating electricity before we go to nuclear".
Mr Cameron meanwhile stressed the "enormous contribution" he believes local councils can make to slashing carbon emissions.
In a speech to the Local Government Association's annual conference he said: "In Britain we are still lumbered with the same backward-looking, central-planning mindset that has dominated thinking on electricity since the first half of the last century.
"There will always be a need for a robust and secure National Grid; energy security is vital.
"But it is a myth that it can only be provided from remote and inefficient power stations or that electricity has to travel hundreds of miles to market.
"We live in a fast-changing world of scientific research and innovation. I want Britain to be at the forefront of the green energy opportunity and I want local government to be in the forefront of Britain's environmental progress.
"We need to think in an entirely new way about energy. The future of energy is not top-down, it's not centralised - it's bottom-up and decentralised."
The interim report of the Tory energy review states that when it comes to nuclear power there would have to be "total transparency" on its full lifetime costs, clarity over nuclear waste and no subsidies or special favours.
"Where the government sees nuclear power as the first choice, under our framework it would become a last resort; where the Liberal Democrats rule out nuclear power, we rule out subsidies and special favours for nuclear power."
The report points out that Britain is "increasingly dependent on imported fossil fuels for power generation" and says the country increasingly at risk from terrorist attempts to interrupt source supplies.
Mr Cameron says Britain's stance on electricity is "backward-looking"
It also argues that green energy options are on the brink of a scientific and technological revolution that could transform both effectiveness and affordability.
"We therefore believe it is now vital to give green energy a chance to demonstrate its potential on a level playing field with other sources of electricity."
Trade and Industry Secretary Alistair Darling it was very difficult to see how the Tory policy could do anything but harm if green energy needed to be put on a level playing field.
"When you aren't prepared to support low-carbon renewable energy, you're going to get higher carbon emissions. It's not that complicated," he said.
"If Cameron is going to talk green, sooner or later he's going to have to do something green. Scrapping the Climate Change Levy and undermining renewables moves us further from a green future not towards it."
Earlier this week the prime minister told MPs he had changed his mind in the last three years on the need for new nuclear power stations.
An Energy White Paper in 2003 was sceptical about building new nuclear plants, but left the option open.
A government energy review, due this month, is expected to call for additional nuclear power stations.