David Miliband has said he is not opposed to a new generation of civil nuclear power stations.

As the government's energy review prepares to report this summer, the environment secretary said he was "open minded" on the issue.

His predecessor in the post, Margaret Beckett, was thought to be sceptical about a fresh boost to nuclear power.

The reshuffle, however, appears to have further opened the door to atomic energy.

Tony Blair is also widely believed to be in favour of replacing the UK's existing nuclear power stations as they reach the end of their working lives.

Speaking on Friday, Miliband said it would be wrong to rule out such an option.

"I am open-minded about how we meet the climate change challenge," he told BBC Radio 4's Today programme.

"Obviously the benefit of nuclear power is that it emits zero carbons but obviously there are costs associated with nuclear power and there are also waste issues, which are very important.

"If you believe that climate change is the number one issue facing the planet, which I do, it seems to me I cannot come and say 'by the way, I have taken off the table one way in which to generate power in a zero carbon way'."

The environment secretary also said he was committed to tackling global warming.

He said that delivering environmental sustainability "is as big a challenge in the 21st century for people on my side of politics as the drive for social justice was in the 20th century".

"Throughout the 20th century people from the progressive side of politics established a social contract, a welfare state, to bring forward social justice," Miliband said.

"In the 21st century we need to establish an environmental contract that is as enduring, as deep, as the social contract that was established."