Britain world's first country, cutting green house gases 80% by 2050

A legally-binding commitment

The pledge came as European Union leaders said they would stick to their target of slashing carbon dioxide emissions by 20% by 2020.

Italy and Poland said the tough standards would be unaffordable during global downturn.

New Energy and Climate Change Secretary Ed Miliband told MPs an amendment to the Government's Climate Change Bill will increase the UK's target for emissions cuts in all greenhouse gases by 2050 from 60% to 80%, compared to 1990 levels.