By Andrew Warshaw at the Main Press Centre on the Olympic Park in London

Rule 40August 7 - The International Olympic Committee (IOC) today launched a strong defence of its strict sponsorship rules after several athletes, mainly from the United States, questioned why they could not mention their individual commercial backers, on whom they rely for funding, on social networking sites or identify them on their uniforms.

Rule 40 of the Olympic Charter says only official Games sponsors can be named and Timo Lumme, the IOC's director in charge of marketing services, says that is how it should remain.

"One of the pillars as regards to the funding of the Olympic Movement are the sponsors, both globally and locally," he told a briefing here.

"At the end of the day we have to make sure their commercial rights are protected - but in a measured way."

Athletes who break the rules can be fined or potentially disqualified depending on severity.

Lumme explained that if the law was changed to allow rival companies to be marketed and promoted by their individual clients, it could affect the entire Olympic Movement.

"For the funding model to survive you need a level of exclusivity...and the athletes, in some way, are asked to respect that," he said.

The debate over individual sponsorship during the Olympics mirrors, in some way, the question of compensation for football clubs who release players for the World Cup and European Championship.

Athletes including Dawn Harper (pictured), gold medal winner in the 100 metre hurdles in Beijing four years ago, used the social networking site to call for the restrictions to be relaxed.

"I am proud to be an Olympian but #wedemandchange #rule 40," Harper tweeted.

Sanya Richards-Ross_celebrates_winning_London_2012_400m_August_5_2012Sanya Richards-Ross, seen here celebrating winning the 400m at London 2012, has been a leading member of the group of athletes wanting IOC Rule 40 scrapped

Another leading voice in the protest has been Sanya Richards-Ross, who won the 400m gold medal here.

Several German athletes also got on board as did American middle distance runner Nick Symmonds who tweeted: "#Rule40 can kiss my temporarily tattooed butt. I wouldn't be in London today without my sponsors!"

While they may not be allowed to showcase their own commercial backers, Lumme argues that the very taking part in the Olympics enhances athletes' profiles.

"You are only talking about two weeks in four years," he said.

"I think that you will often see that those athletes that are lucky enough to have sponsors are also able to profit and prosper from the exposure that they get at the Olympic Games," he said.

"So it is in some ways a fragile ecosystem that requires a level of solidarity and cooperation."

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