"Over the next ten years, nuclear power cannot contribute either to the need for more generating capacity or to carbon reductions as it simply could not be built in time," said the report entitled "Keeping the Lights On".

"Nuclear power raises a variety of issues which would need to be satisfactorily resolved before any decision to go ahead is taken," it added, citing questions of long-term waste disposal, public acceptability, and the availability of uranium.

Published just 10 days before the 20th anniversary of the Chernobyl nuclear disaster, the report also raised questions of safety, terrorism and the risk of nuclear proliferation.

The report is the second time a government body has come out against a new generation of nuclear power stations.

The government, which has acknowledged it is likely to miss its own goal of cutting carbon dioxide emissions by 20 percent by 2010, is half way through a six-month review of the country's future energy needs and how to meet them.

Bound by pledges to slash emissions of greenhouse gases from burning fossil fuels, it must decide the shape of the country's electricity supply network for coming decades as demand grows and North Sea oil and gas run out.

Nuclear and coal power plants supply about 60 percent of Britain's electricity.

"For nuclear power to be economic there have either to be huge subsidies or government guarantees," Simon Shackley from the Tyndall Centre for Climate Change Research told Reuters.

On one side is "big power" promoting coal and nuclear generation. On the other, the green alternative advocating a wider mix of power sources including turning homes into mini power stations using solar panels and roof-top windmills.

"If we are going to have a sustainable, low-carbon society then we have to have low-carbon citizens," said Philip Sellwood, head of the Energy Saving Trust (EST), a body which promotes energy efficiency.

The parliamentary report noted that within a decade one quarter of the country's electricity capacity would be closed down, with the same amount again going offline by 2025.

The report warned that with the nuclear industry's chequered financial and operational performance record, significant government subsidies would be needed to entice private finance.

It also said a decision to go nuclear would rob alternatives like carbon capture and storage to create so-called clean coal, renewables and energy efficiency of the pump priming they need.

Public opinion has swung gradually back in favour of nuclear power, but only when taken as an option against global warming.

The Group of Eight leading industrialised nations -- Britain, the United States, Japan, Germany, France, Italy, Canada and Russia -- are widely expected to endorse nuclear power at a Moscow summit in July.