Perhaps Jacques Chirac was just trying to be polite to his host when he dismissed Finnish cooking as the worst in the world on a visit to the Russian enclave of Kaliningrad this week. After all, there's nothing that the Finns can cook that the Russians cannot cook even worse.

Even so, it is a quip that could cost France dear when the 100-plus voting members of the International Olympic Committee have to choose tomorrow between Paris, London, Madrid, New York and Moscow to host the 2012 Summer Games.

Despite its small population, Finland has two IOC members: the former yachtsman Peter Tallberg, and Jari Kurri, an ice hockey star who won the Stanley Cup five times as Wayne Gretzky's linemate at the Edmonton Oilers.

Unlike the IOC members from France, Britain, Spain, the United States and Russia, both Mr Tallberg and Mr Kurri will be voting from round one. Between them, the pair represented their country at no less than seven Olympic Games and they may not be best pleased by M Chirac's decision to single out Finland's national cuisine as the worst on the planet.

On the other hand, it is quite possible that both the Finnish IOC members were already backing the London bid. IOC members guard their voting freedom zealously and national or regional blocs can be deceptive.

With less than 24 hours until the Committee chooses between the five rivals in what has been one of the most hotly-contested votes in IOC history, London bid officials were trawling through the lists today to see which, if any, IOC members could still benefit from a London sales pitch. Tony Blair left Singapore in the early evening, local time, after three days of assiduous plugging for the UK candidacy.

The bidding rules have been tightened up considerably since the Salt Lake City vote-buying scandal that saw ten IOC members expelled and the whole Olympic movement shamed. Bidding cities are not allowed to entice national Olympic committees with scholarship schemes or IOC members with expenses-paid holidays.

In fact the current IOC meeting in Singapore has represented the first real chance for bidding cities to appeal personally to IOC members, making the Prime Minister's presence in the city two days before M Chirac potentially invaluable.

The IOC has 116 members, two of whom are missing from Singapore, including Guy Drut, the former French hurdler who is caught up in a corruption case. Another, Bulgaria's Ivan Slavkov, has his voting rights suspended and Jacques Rogge, the IOC President, cannot vote except in the event of a last-round tie.

Members from countries with candidate cities, who number 14 including M Drut, cannot vote until those cities are eliminated, meaning that 99 will take part in the first round of the secret electronic ballot at the Raffles conference centre at 10.45am UK time. One city is eliminated after every round and the number of voters increases until a city wins a clear majority. The result will be announced at about 12.45 UK time, live on global television.

M Rogge, a Belgian, predicted earlier this week that the final result could come down to a handful of votes. Kevan Gosper, a senior IOC member from Australia, said today that he expected the contest to go right down to the wire, with a final round of voting between London and Paris.

But the IOC members - whose sole power comes from the fact that they choose Olympic host cities - are a sophisticated and unpredictable electorate who can cause an upset just by voting tactically - or by trying to send a signal for the future - in the early rounds.

Reports from Singapore suggest that Juan Antonio Samaranch, the Spaniard who is the IOC's honorary life president after leading the organisation for two decades, has been urging members not to allow Moscow - which has technically the least developed bid - to slump out in the first round. Senor Samaranch's son, Juan Antonio Samaranch jr, succeeded his father on the IOC and is strongly pushing the Madrid bid.

Likewise, New York is not seen with much of a chance of progressing beyond the second round of voting - but its supporters will want to ensure that it goes down fighting, even if they already know which way they will vote in later rounds. Sentimental voting in any round, but especially in the second or third, can distort the result irrevocably.

The one fact that should give Sebastian Coe, the London bid leader, confidence when he gets up to lead the formal presentation of the UK bid tomorrow, is that favourites rarely do as well as expected in Olympic beauty contests.

Of the past four cities chosen to host the Summer Games - Atlanta, Sydney, Athens and Beijing - only Beijing started the final contest as favourite, after being pipped at the post by Sydney for the chance to host the 2000 Games.