Emissions to be cut by 80 percent

"In a decade in power Labour has never adopted a target so ambitious, far-reaching and internationally significant as this," said Greenpeace chief scientist Dr Doug Parr.

FEED-IN TARIFFS

Miliband also said he would amend a new energy law being debated to introduce 'feed in' tariffs for small-scale renewable energy generation. He did not specify which technologies.

Feed-in tariffs pay people a premium to generate "green" electricity and feed this back into the national grid, earning them a profit which helps to pay for installing solar panels, wind turbines, groundwater heating systems and other sources.

The measure could be a big boost to installers of such renewable power, such as Centrica's British Gas arm.

"The provision of a feed in tariff is crucial to the success of microgeneration technologies, which have a key role to play in meeting the government's renewable energy and carbon emissions targets," said Gearoid Lane, managing director of British Gas New Energy.

Miliband said he would make a separate announcement on boosting renewable heat.

The chief adviser on climate change, Adair Turner, last week recommended the more ambitious 2050 goal, which is an 80 percent cut compared to 1990 levels.

The new emissions target would apply to all six greenhouse gases defined under the United Nation's Kyoto Protocol, not just carbon dioxide as formerly.