Today marks the final frenzied stage of lobbying as the International Olympic Committee prepares to choose a host for the 2012 Olympics.

Muhammad Ali arrived in Singapore Tuesday to lobby for New York City's bid, along with Sen. Hillary Rodham Clinton. Soccer superstar David Beckham arrived as well to back London's bid, as did his Real Madrid teammate Raul Gonzalez who's supporting a rival bid from Madrid.

At this point, oddsmakers are continuing to pick Paris as their favourite, followed ever more closely by London.

New York may prove to be a dark horse, some speculate, while Moscow and Madrid are considered longshots.

IOC President Jacques Rogge formally opened the selection session Tuesday evening with a ceremony at a downtown Singapore concert hall. In a speech to the members, Rogge suggested that the four cities that lose out this time should consider bidding again for the 2016 Games.

"They should know that the quality of their candidature file would give them an excellent chance,'' he said.

The selection committee will decide the winner based on such things as sports facilities, security, public transportation, and athlete housing.

The committee vote will be held at 5:45 p.m. Wednesday evening (5:45 a.m. ET Wednesday), with the winner announced at 7:30 p.m. (7:30 a.m. ET).

CTV's Canada AM will provide live coverage.

Bob Steadward, a former IOC member who took part in 1996 Toronto Olympic bid, believes that any of the bidding cities could win.

"These Olympic bids have surprised people every time there's a vote every couple of years. So I wouldn't necessarily put money on any one of those cities right now," he told CTV's Canada AM.

"You have to realize that all five of these candidate cities have not only met, they have likely far exceeded all of the basic criteria that are expected to buy the IOC."

Competition for the bid has grown tense in recent weeks, with frontrunners Paris and London engaging in a nasty war of words.

According to reports, two consultants to the London bid -- Jim Sloman and Rod Sheard -- criticized a stadium that is the proposed focus of Paris' plans.

Rules set out by the IOC forbid candidates from criticizing a rival city.

Paris has said it won't issue a complaint with the IOC ethics commission.

"It's not up to Paris to interpret the rules; that is a matter for the IOC,'' Paris Mayor Betrand Delanoe said. "On our part, it will be fair play throughout. We will not be belittling the others.''

Then, French President Jacques Chirac tossed a few insults toward London, according to newspaper reports.

During a conversation with German Chancellor Gerhard Schroeder and Russian President Vladimir Putin, Chirac expressed his opinion of British cuisine, the French newspaper Liberation reported.

"We can't trust people who have such bad food,'' Chirac was quoted as saying. He added that mad cow disease was Britain's sole contribution to European agriculture.

British newspapers eagerly rose to the bait.

"Don't talk crepe, Jacques!'' scorned The Sun.

London and Paris have each hosted the Olympics twice before -- 1948 was the last time for London, while Paris last hosted the Olympics in 1924 (Albertville hosted the Winter Olympics in 1992).

Moscow hosted the Summer Games in 1980, but the affair was marred by a boycott by countries like Canada and the United States over the then-USSR's invasion of Afghanistan.

Madrid and New York have never hosted a Summer Olympics. The Summer Games were last in Spain at Barcelona in 1992 and in the U.S. at Atlanta, Ga. in 1996.

The schedule of Wednesday's IOC meeting to decide the host city of the 2012 Summer Games:

• 9 a.m (9 p.m. ET Tuesday): Presentation by Paris
• 10:30 a.m. (10:30 p.m.): Presentation by New York
• 12 noon (midnight): Presentation by Moscow
• 2:30 p.m. (2:30 a.m. ET Wednesday): Presentation by London
• 4 p.m. (4 a.m.): Presentation by Madrid
• 5:15 p.m. (5:15 a.m.): Report by IOC Evaluation Commission
• 5:45 p.m. (5:45 a.m.): Vote to elect the 2012 host city
• 7:30 p.m. (7:30 a.m.): Announcement ceremony
• 8:30 p.m. (8:30 a.m.): Signature of host city