Could the man who "used to be the next American president" really be America's next president?

News today that Al Gore had picked up the Nobel Peace Prize for his advocacy on global warming set alarm bells ringing at one London bookmakers, which had offered 100-1 on Mr Gore achieving an unimaginable trifecta: Oscar, Nobel prize and White House.

Mr Gore had already picked up an Oscar for his climate change documentary, An Inconvenient Truth, and after hearing that he had fulfilled the second condition Ladbrokes made him an 8-1 shot to win the presidency next year - although Hillary Clinton remains the odds-on favourite.

“He seems to have the Midas touch and if his supporters encourage him to stand he may shake up the whole race,” said the firm's spokesman, Robin Hutchison.

Earlier this week, a group of US Democrats placed a full-page advertisement in the New York Times urging Mr Gore to jump into the race for the White House. In an open letter, they told him “your country needs you now, as do your party, and the planet you are fighting so hard to save”.

The organisation, draftgore.com, which describes itself as a group of grassroots Democrats, added: “America and the Earth need a hero right now, someone who will transcend politics as usual and bring real hope to our country and to the world.”

Mr Gore has said repeatedly that he does not “have any plans to be a candidate again”, but his supporters - 136,000 have signed the draftgore petition - are hoping that the Nobel win will help them to forget the trauma of 2000 and change his mind.

"This award will only add to the tremendous tidal wave of support for Al Gore and the growng demands that he become a candidate for President in 2008," draftgore.com said in a statement today.

"He is in a unique position to make a difference in the world on the one issue he believes to be the most important of our times. We believe that under these circumstances he has no choice but to take the one step left to have the greatest impact in changing policy on global warming - run for President."

That anyone is talking seriously about a Gore tilt at the presidency shows how complete a transformation the 59-year-old he has achieved from wooden politician to rock-star like environmental champion.

After An Inconvenient Truth picked up the best documentary Oscar in Februrary, Mr Gore went on to be the headline speaker at the worldwide series of Live Earth concerts. He has also seen his book The Assault on Reason - an extended rant against the Bush administration - make it to the top of the best-seller lists.

Although he is not an official presidential candidate, opinion polls show Gore ranking third among Democratic contenders with 10-12 per cent, roughly the same as the hard-running John Edwards.

Among those encouraging him to run is Jimmy Carter, the former president and fellow Nobel peace laureate, who said earlier this year: “I’ve put so much pressure on Al to run that he’s almost gotten aggravated with me."

Analysts agree that the former vice-president would face a daunting task if he jumped into the Democratic race dominated so far by Senator Clinton - as well as alienating his former boss.

Fewer than three months before the first nominating contests, it would be virtually impossible for Mr Gore to match Mrs Clinton's $70 million war chest or the $75 million raked in by her rival, Senator Barack Obama.

He might also have left it too late to build a national campaign organisation that would allow him to target the key states. .

The main question, however, is whether he would want to run. In an interview with Time Magazine in May, Mr Gore remained open. “I haven’t ruled it out, but I don’t think it is likely to happen,” he said. “If I do my job right, all the candidates will be talking about the climate crisis. And I’m not convinced the presidency is the highest role I could play."

His wife Tipper said several close friends had tried to get Mr Gore to take the plunge but he had little reason to heed their urgings.

“He’s got access to every leader in every country, the business community, people of every political stripe,” she said.“He can do this his way, all over the world, for as long as he wants. That’s freedom. Why would anyone give that up?"

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