The Australian Commonwealth Games Association said cramped conditions -- with 6000 people living on 20ha -- could affect performances unless the Bracks Government acts.

"If Ian Thorpe goes for a training swim at six in the morning and then wants to have a sleep, and he can't because of the noise or whatever, that would be a disaster," said ACGA president Sam Coffa, also deputy chairman of the Melbourne 2006 board.

Concerns include a jumble of jam-packed permanent and portable houses, a lack of open space, no airconditioning, up to three athletes per bedroom and 27 in a house with one living room.

The fears have surfaced after a series of site inspections at the village.

The Bracks Government is a partner with the ACGA in delivering the $1.1 billion Games in March 2006.

The Herald Sun understands a Cabinet sub-committee has knocked back a recommendation to move some of the planned 200 portable homes to adjacent land -- for fear of offending greenies.

"Melbourne 2006 is supposed to be the athletes' games, but the actions don't support that regarding the village at the moment," ACGA chief executive Perry Crosswhite said.

"Our concerns are congestion and noise. The site has a lot of housing concentrated in a small space."

"There is no airconditioning so people will have to open windows, so it's going to be noisy. There's only one room for people to congregate in their residential environment -- that's for households of up to 27.

"Squeezing in all those people and facilities on that (20ha) footprint, it just seems that congestion and noise are going to be significant, and we're going to have a look at it."

Mr Crosswhite and Mr Coffa sit on the M2006 board chaired by the Government's appointee, Ron Walker.

Sources said other countries, including New Zealand, England and Scotland, were also developing a plan B.

Up to 4500 athletes and 1500 officials will be housed at the village.

About 200 portable homes will be located around 150 permanent houses.

The ACGA said overcrowding could be avoided by moving portables across Oak St to sports fields and an area set aside to be developed as wetlands.

The ACGA, the international Commonwealth Games Federation and the Government's Office of Commonwealth Games Co-ordination are believed to have backed the plan.

But State Cabinet's Commonwealth Games sub-committee, headed by Treasurer John Brumby, torpedoed the move in August.

It is claimed the Government was concerned about giving campaigners against the Parkville site and green groups ammunition by moving outside the original 20ha precinct.

"We do not intend building on the parkland," Commonwealth Games Minister Justin Madden said yesterday.

"We've always maintained and continue to maintain the village will be developed on former government land -- the former psychiatric site."

Mr Madden said he did not believe there would be any problems come March 2006.

"We think it is the best Commonwealth Games village ever developed," he said.

"Commonwealth Games villages are always crowded."

There are 155 permanent houses and 80 apartments scheduled to be built by November next year.

They would accommodate about 4740 athletes.

About 200 temporary homes would house another 1260 competitors and officials.