Coates, the President of the Australian Olympic Committee and a senior member of the International Olympic Committee, has offered his backing to the World Cup bid after they were cleared by the Government of any financial irregularities following a series of allegations in newspapers owned by the Fairfax group, including the Sydney Morning Herald and The Age.

Coates, who overcame the odds when he led Sydney's bid to stage the 2000 Olympics to victory over hot favourites Beijing in 1993, has a unique understanding of how major international campaigns to stage mega-events work.

He said: "All of these events are massive international sporting events and it requires an all-out effort to win the right to host them.

"There are very clear rules of engagement which must be observed, but you must also execute the campaign with enthusiasm.

"Australia is up against very fierce competitors and we can't enter these contests with a timid approach.

"There will always be sinister forces trying to undermine the bid and the Australian media should not be so naive as to play into their hands.

"And now that the Government has re-affirmed its satisfaction with FFA's (Football Federation Australia) financial and accounting practices, it's time the whole country got behind the bid."

Australia is one of the favourites to host the 2022 World Cup, along with the United States, but also faces strong competition from Qatar, who are bidding to become the first Middle East country to stage the tournament.

Coates said: "This is not a game of marbles.

"It's played for big stakes by some very tough competitors.

"There are no quarters asked, and none given, and FFA has to stick to its guns if it wants to win."

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