John Prescott is to return to frontline politics ahead of the General Election after Ed Miliband appointed him a climate change adviser.
The former deputy prime minister will be working with heads of state and foreign governments to "raise their ambition", according to the Labour leader.
He wants Lord Prescott to work on an agreement in the run-up to a crucial United Nations summit in Paris at the end of the year.
Mr Miliband said he was inspired to appoint the life peer because of his experience in getting an agreement at the landmark Kyoto Protocol in 1997.
Lord Prescott became known during the premiership of Tony Blair for his pugnacious style and is considered a formidable negotiator.
Writing in The Observer, Mr Miliband said: "His abilities and experience... must be used at this critical time for our future and there is no one better than John at bashing heads together to get a deal."
In his column in The Sunday Mirror, Lord Prescott said he will continue to work with politicians from around the world.
He said: "For the last two years, I've spent my time trying to get agreement from elected parliamentarians around the world.
"From Mexico, to India and Europe, politicians have agreed it could be a way forward. But now we need to get the world leaders involved."
He said he was prepared to work with the current coalition Government in order to try to get a deal in Paris.
Mr Miliband said that following last year's floods climate change had become an issue of national security for Britain.
It would be a "disaster" if the summit failed to achieve a meaningful agreement, he added.
"There is a real danger that this great chance to achieve action is going to slip by, without the world even noticing."
"I do not want to see Britain or any country having to adopt crisis measures to halt the slide into global catastrophe because we missed this critical opportunity now," he said.
Mr Miliband said he would use the talks to push for ambitious carbon emissions targets for all countries.
Shadow foreign secretary Douglas Alexander told Sky's Murnaghan programme: "I certainly remember the thumping victory in 2001 and the key role that John played there.
"The truth is John has for many years been one of our strongest campaigners and I think whether it's his work on social media or whether it's his work motivating supporters over many years, he's done a fantastic job.
"The role and brief that John has been given right now is to focus on climate change, but I fully expect that as well as that policy role he'll continue to support the Labour campaign in the months ahead and I certainly welcome that."
Former Labour director of communications Alastair Campbell also welcomed the move, saying on the BBC's Andrew Marr show that Lord Prescott was "absolutely brilliant" when the Kyoto protocol on climate change was being negotiated when the party was in power.
