Rows over the future of energy were raging last night as the government came under fierce attack after launching a five-month consultation on the "significant role" new nuclear power stations could play.

Opposition parties, environmental campaigners and pressure groups criticised ministers for peddling a "failed policy", questioning where new nuclear power stations would be built.

Trade and Industry Secretary Alistair Darling said it was "more likely than not" that any new nuclear power stations would be built on the sites which already have similar plants.

But Greenpeace said an official report published after a Freedom of Information request by the group showed that sites in the South, including Hinkley, Sizewell, Dungeness and Bradwell, were considered as the most suitable places for new reactors.

Director John Sauven said: "Scientists say the speed at which climate change is happening means that some of the sites suggested for new nuclear power stations are threatened by rising sea levels and storm surges.

"Meanwhile political developments in Scotland have ruled out other sites. You have to question where the Government thinks it's going to build these things.

The government also came under fire over plans for a £14 billion barrage across the Severn that would harness the tidal energy of the Severn Estuary, which Mr Darling said he was "very interested" in promoting.

The Royal Society for the Protection of Birds warned that the 10-mile barrage would cause "untold damage" to the environment.

A public consultation will run until October 10.