The SNP accused the Coalition Government of subsidising nuclear power through the back door last night after it published plans to drive millions of pounds of investment into a new generation of power stations.

Mike Weir, the party's energy spokesman, said UK ministers were "obsessed" with the energy source, which they were "plainly subsidising".

The row erupted after the Coalition published proposals to give nuclear power and renew-ables an advantage over coal and gas through a new carbon floor price. Ministers insist the move is necessary to deal with a looming energy gap in the UK. However, environmental campaigners accused the Coalition of "rigging" plans in favour of nuclear power at the expense of renewables.

WWF Scotland warned that a "dilution of focus" could jeopardise the Scottish Government's 100% renewables target.

There were also warnings the proposals, contained in a draft Energy Bill, could drive up the average heating and electricity bills, although ministers insist the changes will cut costs in the long term.

Other proposed reforms would do nothing to help deliver fair energy prices, Labour warned.

The Scottish Government is opposed to new nuclear power and can block any plan to build plants north of the Border.

Although the Coalition Government backs a new generation of nuclear power stations, ministers say they will receive no Government funding. Instead they unveiled plans yesterday to drive £110 billion of investment into new plants and renewable energy through a series of reforms, including the carbon floor price.

This would guarantee com-panies a steady return on the high investment needed to build new nuclear power plants and offshore wind farms.

However, the SNP accused the Coalition of being "obsessed" with nuclear energy.

"The proposed contracts ... are plainly a subsidy for nuclear, despite the fact that the industry has swallowed billions of pounds of public money over many years," Mr Weir said.

Labour's Shadow Energy Minister, Tom Greatrex, said the proposals would do nothing to help hard-pressed families and businesses. But he praised the drive to attract investment to low carbon technology.