A proposal had been put before the 60th FIFA Congress in Johannesburg today to make the tournament an under-21 event. Blatter suggested this had been put forward because of the tight international calendar.

The International Olympic Committee had warned that any change could affect the number of teams allowed in the football tournament in the future, and Blatter admitted his IOC counterpart Jacques Rogge had been angered when he heard about the proposal.

But FIFA's member associations responded by voting 89% in favour of maintaining the current age limits and Blatter was delighted.

Blatter said: "When such an idea came on the table of the IOC in Lausanne, there was a fire in the organisation of the Olympic Games and I had a very angry President Rogge coming to Zurich to have a look.

"Sometimes when we have such revolutionary ideas, a little bit of conservatism will be the winner. And if you ask any player, if they have participated in Olympic Games, they are all happy to go and play once in the Olympic Games."

The prospect of some legal challenges ahead of London 2012 appears probable as a result of today's decision - Barcelona and German sides Werder Bremen and Schalke all won a ruling in the Court of Arbitration against FIFA in 2008 against being forced to release their players for the Beijing Games.

CAS ruled that as the Olympics were not on FIFA's international calendar the clubs were not obliged to release the players.

Denis Oswald, the chairman of the IOC's co-ordination commission for London 2012, was in Johannesburg today for the FIFA Congress to witness the vote.

Blatter told Congress delegates that football had a privileged position as the only team sport with 28 national teams taking part in the Olympic competition.