Formula One could collapse after next year if the sport does not make drastic spending cuts, according to FIA president Max Mosley.
Mosley said the cost of running a Formula One team has now put the entire sport at risk, citing the recent exit of Japanese team Super Aguri due to a lack of funds.
Mosley, who will stand down from his role next year, said more teams may also withdraw from the sport soon.
"I think it would put the sport in an unsustainable position if we lost two more teams," Mosley told BBC Sport.
"At the moment we have 20 cars competing and if we lost two teams we'd have 16 and then it would cease to be a credible grid.
"Some of the manufacturers are already having difficulty if you look at their share prices.
"This hasn't been prompted by the credit crunch. This is something I have been campaigning for for two or three years.
"It had become apparent long before the present economic difficulties that Formula One is unsustainable.
"If we can't get this sorted out by 2010 we will be in serious difficulty.
"We can survive through 2009, but I'm not too sure about after.
"It now depends on billionaires subsidising teams."
