A last-ditch effort is being made to insert clearer green commitments into the global economic recovery package. The move comes amid fears amongst some British government officials that the G20 summit is in danger of missing a unique opportunity to prevent the world from being locked into irreversible and catastrophic climate change.

British Prime Minister Gordon Brown Monday promised that a commitment to tackle the environment will be one of the five tests of the communique due to be released following the summit on Thursday, adding "there were long hours of hard negotiations ahead".

Number 10 counseled caution insisting that the main climate change event of the year will be at Copenhagen in December, when the U.N. hopes to reach a global deal to replace the Kyoto agreement.

The draft G20 communique leaked over the weekend makes only the smallest reference to climate change, and appears to be vague on the subject of how green the $2 tillion (£1.4 trillion) stimulus package agreed by world leaders should be.

This provoked the eminent climatologist James Hansen, director of NASA's Goddard Institute for Space Studies, to tell the Guardian: "If this is the best they can do, then their 'planet in peril' rhetoric is probably just that - empty rhetoric."