Greenpeace have said a leaked draft of the government's energy review shows ministers are not ruling out building new nuclear power stations to meet Britain's future energy needs.

Publishing what it claims is a leaked summary of the energy review conducted by the Cabinet Office-based performance and innovation unit, Greenpeace said it was concerned that up to a dozen new nuclear plants could now be built.

The leaked report says that energy policy will be directed towards reducing Britain's carbon emissions, a requirement of the Kyoto agreement on tackling global warming.

There should be tougher targets for energy efficiency and measures to promote the use of renewable energy, says the draft report. It backs a 20 per cent share of the energy market for "green power" by 2020.

On the controversial subject of nuclear power, the reports says the government will be in a position to influence the future direction of the industry.

"The decision whether to bring forward proposals to bring forward proposals for new nuclear build will lie with the commercial sector. Nowhere in the world have new nuclear stations yet been financed with in a liberalised electricity market," says the report.

"But, given that the government sets the framework within which commercial choices are made, it could, as with renewables, make it more likely that a private sector scheme would succeed."

The draft report says the main focus of public concern about nuclear power is the issue of long-term disposal of radioactive waste. It says that if all current nuclear power stations were replaced, there would only be a 10 per cent increase in the total amount of waste.

"Any move by the government to advance the use of nuclear power as a means of providing a low carbon and indigenous source of electricity would need to carry widespread public acceptance, which would be more likely if progress could be made on dealing with the problem of waste."

"Public acceptance would need to be built on an open and transparent debate," says the leaked study.

Greenpeace said the statements marked a U-turn on Labour's 1997 manifesto statement that there was "no economic case" for building new nuclear power stations.

Greenpeace executive director Stephen Tindale said the report was "a catalogue of missed opportunities".

"It leaves the door open for a new wave of dangerous nuclear power stations, which will affect our health, endanger our security and pollute the environment for generations to come," he claimed.

"Its timid targets for renewable energy miss the chance to take advantage of Britain's huge potential for wind and wave power. The government can't have its cake and eat it - it can prop up the nuclear industry or it can develop world leading renewable energy."

The Conservatives urged the government to set out their position at the earliest opportunity. Shadow energy minister Robert Key said the government should "put up or shut up".

"Drafts of this report have been leaking for months. The management of this review by the DTI and the Cabinet Office has been incompetent and the uncertainty is now damaging the British energy industry. Ministers must make a statement to the House at the earliest opportunity," he said.