Number 10 says “wishful thinking will not keep the lights on”, as plans to give the go-ahead to a new generation of nuclear power stations are outlined.Tony Blair says the UK needs a mixture of energy sources to lessen reliance on imports and to address climate change.

Critics say nuclear power is dangerous and not the answer to climate change.

Trade and Industry Secretary Alastair Darling is outlining the government’s energy strategy for the next 30-40 years in the House of Commons.

An Energy White Paper in 2003 said better efficiency and investment in renewable forms of energy were the way ahead for the UK.

But the prime minister ordered a new review last November, saying a fresh look was needed at how the UK could ensure it had a secure energy supply and meet its targets for fighting global warming.

The study was controversial from the outset when Greenpeace protesters delayed Mr Blair’s announcement by invading the roof of a conference hall.

Since then Mr Blair has been accused of prejudging the review by saying that nuclear power was back on the agenda with a “vengeance”.

The prime minister, on a visit to an offshore windfarm near Whitstable, Kent, stressed the urgency of making decisions on rejuvenating Britain’s energy supplies, saying he wanted to see renewables grow by five times in the next 15 years.

“It’s not a question of either/or - it’s everything that’s got to be done to make a difference,” he said.

“We’re about to move to a situation of importing energy. We have to at least replace our nuclear power stations. These decisions have to be taken now.

“Fifteen years down the line we have got high energy prices and real problems.”

His spokesman said: “Wishful thinking will not keep the lights on. You have to think hard about the energy gap. The reality is, if we do nothing, the amount of energy we get from nuclear will decline from 20% to 6%.

“What you will see in the energy review is that there will be a big increase in renewable energy. There will be a big increase in energy efficiency moves and that will deliver more electricity, but that in itself will not be enough to make up the shortfall and therefore you do need nuclear.”

Renewables

Department of Trade and Industry officials say the review also looks at how the UK can meet its target of cutting carbon emissions, blamed for global warming, by 60% by 2050.

Energy supply is another major concern for the government with the UK becoming more reliant on imports. Officials say the UK imported 10% of its gas last year but without changes that could rise to 90% by 2020.

Energy Minister Malcolm Wicks has looked at how to boost renewable energy sources, such as wind, wave and solar power, as well as cleaning up fossil fuels.

Reducing energy demand through efficiency measures in homes and businesses is another plank of the review, as is charging more for high-polluting ways of generating electricity.

But it is the replacement of existing power stations, particularly nuclear ones, which is likely to dominate the debate.

Opportunity lost?

Mr Darling, who opened his statement to MPs by saying energy efficiency and renewable energy is needed, is expected to say local objections to nuclear and other power plants could be over-ridden under new planning rules.

Local councils could alter the appearance and precise location of the sites but would be unable to reject power plants on the grounds that they were not needed.

Supporters of nuclear power want to have a firm framework on which to make investment decisions.

They insist they will not need government subsidies to build new nuclear plants.

But Tom Burke, a visiting professor of environmental policy at Imperial College and University College London, and a nuclear sceptic, said: “In the real world, if people invest in nuclear, they are not going to invest in renewables.”

Tony Juniper, director of Friends of the Earth, said the review was a golden opportunity to lead the world in developing low-carbon economy.

“We can tackle climate change and meet our energy needs by cutting energy waste, harnessing the power of renewables and using fossil fuels more efficiently,” he said.

“And we can do this without wasting more money on dirty and dangerous nuclear power.”

Conservative shadow trade and industry secretary Alan Duncan said nuclear power should only be a “last resort”.

“What I would like to see is a cross-party consensus to reduce carbon emissions, guarantee affordable security of energy supply and create a level playing field to give a green energy revolution a chance,” he said.

The Liberal Democrats are accusing ministers of “surrendering” to the nuclear lobby, and oppose Mr Blair’s decision “to press the nuclear button”.

The party’s energy spokesman Edward Davey says major investment in clean coal and renewable technologies will encourage private firms to invest, raising cash for government-sponsored research and development.