Gordon Brown faces the biggest test of his environmental credentials this week, with the Government due to give the go-ahead to a new generation of nuclear power stations. John Hutton, the Secretary of State for Business, is expected to make an announcement to MPs on Thursday, outlining the decision to allow private power firms to invest in the UK's first new reactors for decades.

Yesterday Mr Brown listed ensuring the security of Britain's energy supplies as among the long-term decisions needed to be taken as he launched a major political fightback for the new year. Speaking on the BBC's The Andrew Marr Show, he said: "This is a year of very big choices for the British society and for Britain as a whole. It's about equipping ourselves for the future; a year of big long-term decisions. I will be judged by whether I get these right."

Today he will hope to start this process by pledging to shift the NHS towards preventative medicine, through the announcement of the world's biggest screening programme for heart disease, strokes, diabetes and kidney disease.

On Thursday, Mr Hutton will argue that new nuclear power stations are needed to stop the lights going out in the decades ahead. He is not expected to put a limit on the number of new reactors, instead arguing that that decision should be left to the private sector. An energy Bill, due to be unveiled alongside the announcement, will set out rules governing private financing of the reactors and their eventual decommissioning.

Mr Brown used the interview with the BBC to attack the opposition for "ducking" long-term decisions on "energy, Heathrow, transport, infrastructure, housing, planning, education to 18, all the big issues affecting the country". Hailing new legislation to extend the education leaving age to 18 and reiterating the Government's pledge to reform the planning system to build 3 million homes, Mr Brown insisted he would "make the right long term-decisions".

Greenpeace attacked the prospect of new nuclear power stations and lambasted Mr Brown for backing expansion at Heathrow. "Mr Brown is about as green as his name," a spokesman said. "It's no use being strong if you are wrong."

Steve Webb, the Liberal Democrat environment spokesman, added: "Ministers have admitted that new power stations will make little or no contribution to energy supply before 2020. Where is the strategy urgently needed now to tackle the twin problems of climate change and security of energy supply?"

Alan Simpson, the Labour left-winger and environmentalist, said: "The tragedy of Gordon Brown is the only big decisions he appears capable of taking are the wrong ones."

(By Ben Russell, The Independent, 07/01/2008)