London have enlisted Australian Olympic champions Cathy Freeman and Grant Hackett to act as international ambassadors for their bid to host the 2012 Games.
The chairman of the London bid, Sebastian Coe, said he hoped the high profile pair would help London's chances of securing the Olympics when the International Olympic Committee makes its decision in July.
The appointment follows New York's decision to use Australian swimmer Ian Thorpe as one of their ambassadors while former Wallabies World Cup winning captain John Eales has joined the French bid.
"Cathy's on board because apart from the fact she's a very good friend of mine, she believes London is the best place for a games to be hosted," Coe told a news conference on Saturday.
"And Grant also supports the bid and believes he can contribute... and with my background, I don't like athletes just simply being used as expensive calling cards, they need to contribute, they need to know what this bid is about."
Coe arrived in Australia on Saturday a day after his mother's funeral but was able to conceal his grief as he presented London's bid to the general assembly of Oceania National Olympic Committees.
Paris is favourite to win the games but London, which staged the Olympics in 1908 and 1948, has steadily been closing the gap under the astute guidance of Coe, twice the Olympic 1,500 metres champion and now a council member on the world governing athletics body.
Madrid, Moscow and New York are the other cities in the race.
London's hopes of staging the Games seemed a lost cause after the city was stripped of the right to host this year's world athletics championships but Coe said that was now consigned to ancient history.
"Confidence has been restored. We've had a Commonwealth Games (in Manchester in 2002) that has restored our credibility," he said.
"And we've had since then the world indoor championships in Birmingham that is used as a blueprint for future championships."
Keith Mills, chief executive of the London bid, said that more importantly, the IOC was also convinced about London after their inspection of the city.
"When the IOC came to London they could see this park being built in front of their eyes, it's not an illusion... this was real," Mills said."I think we've built a huge amount of credibility over the last year in terms of our ability to deliver on our promises."