In a last push to oust the French capital from pole position, Tony Blair and David Beckham are preparing to sell London as the world's capital of youth in a frenzied round of lobbying.
Mr Blair yesterday claimed that London was the "city that most excites young people the world over" as he flew out towards Singapore, where the vote takes place.
With Paris, the favourite, starting to show signs of last-minute nerves, London is concentrating on its key message that staging the games in Britain will deliver the best legacy for future generations. A team of celebrity lobbyists headed by Beckham will drive home the youth and legacy pitch in the final 48 hours.
Even the Queen was enlisted yesterday to emphasise the message. In a statement released by Buckingham Palace, she said: "As a nation we share a great passion for sport and a desire to see a greater participation in sport, especially among younger people."
The 100 members of the International Olympic Committee entitled to vote in the first round will hear a presentation from a 14-year-old east London schoolgirl, Amber Charles, in support of London's bid. Paris's final pitch, by contrast, is being led by the 72-year-old President Jacques Chirac.
Observers say the youth pitch is well aimed, since the IOC is determined to ensure that global support for the Games transfers to the next generation. Its president, Jacques Rogge, has described this week's contest as one of the closest bidding races in the history of the Games and said it could come down to just "five or six" votes.
Hillary Clinton, Muhammad Ali and Mayor Michael Bloomberg will be lobbying for New York, while Spain's Queen Sofia and Prime Minister Jose Luis Rodriguez Zapatero will be doing the same for Madrid. The Russian Prime Minister, Mikhail Fradkov, will be arguing the case for rank outsider Moscow.
Paris, which last hosted the Games in 1924, is bidding for the third time in recent years after losing out for the 1992 and 2008 Games.
"If I were betting on it, I'd say it's theirs to lose," a Canadian IOC member, Dick Pound, said. "It depends who's the best on the day."
Gerhard Heiberg, an IOC delegate from Norway, said: "I'm not convinced Paris is front-runner any more. Some months ago I felt that, but today I'm not so sure."
In the first round of voting, the candidate city with the fewest votes will be eliminated. The process continues round by round until one city receives a winning majority. IOC members from countries making bids cannot vote, but as a city is eliminated, members from that country can join the voting.
Reports that London and Madrid have agreed to support one another in the event of either being knocked out in an early round are lent credibility by the long friendship between Lord Coe, leader of the British bid, and Spain's Juan Antonio Samaranch.
The former IOC president may command a vital Latin bloc that could see London snatch the prize from Paris.
But there were warnings last night that any such deals could backfire as delegates bridle against being manipulated. One South American IOC member said: "Does anyone really think that we want to be told how to vote by Samaranch or anyone else?"
And despite London's optimism, ministers are quietly preparing the ground should the attempt to stage the games fail. They have asked Patrick Carter, head of Sport England, to prepare to salvage what he can from the bid if the decision goes elsewhere.