Five members - Ugur Erdener of Turkey, José Perurena, Marisol Casado and Juan Antonio Samaranch of Spain, and Tsunekazu Takeda of Japan - come from countries which have a bidding city.

These members will not be permitted to vote unless and until the city from their particular country is eliminated.

Jacques Rogge, IOC President, does not vote in such contests, so as to maintain his carefully-preserved neutrality.

At least two further members - General Mounir Sabet from Egypt and Finland's Saku Koivu - are not expected to be present in Buenos Aires.

That leaves 95 of the 103 current IOC members who may play a direct role in determining which of the three candidate-cities - Istanbul, Madrid and Tokyo - exits the competition first.

It is in theory possible for one of the three candidates to poll an outright majority of votes and hence win in the first round of the competition, but most observers think this unlikely.

These figures make no allowance for King Willem-Alexander of the Netherlands, who recently left the IOC after acceding to the Dutch throne.

Contrary to some expectations, insidethegames understands that the Princess Royal is likely to vote as one of the four British IOC members.

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