The government's chief scientist, professor David King, has urged ministers to help troubled nuclear power company British Energy by exempting it from the climate change levy.

Meanwhile, the government has been criticised by trade union leaders for loaning British Energy £420 million at the same time as rejecting calls to renationalise Britain's railways.

Bob Crow, general secretary of the RMT, said: "If we can bring the lame ducks back into public ownership then why can't we take the white swans?"