Eddie Jordan (left) and Paul Stoddart's teams are under threat

Ecclestone said he believed both Minardi and Jordan would find it "not easy to survive".

But Stoddart responded: "He has no right to say that. Minardi will be on the grid in 2005 in Melbourne."

Jordan boss Eddie Jordan said he would "fight tooth and nail" to be on the grid next season.

Doubts over the teams' futures have been heightened by Ford's decision to pull out of Formula One at the end of the season.

Jordan and Minardi both have engines supplied by Ford-owned Cosworth Racing, which is now for sale.

I can assure you that Minardi will be on the grid in 2005 in Melbourne, even if we have to do it with our own engine Minardi boss Paul Stoddart Teams plan Cosworth talks

The teams are currently trying to come to an arrangement to continue using the engines, which are supplied at a reduced rate.

Ecclestone believes there could be as few as 10 teams on the grid at the start of next season, with Ferrari, Williams and McLaren potentially racing three cars to boost the numbers.

Jordan admitted he was not in a position to guarantee the future of his team.

"If one has to be realistic about the situation, I'm an absolute fighter. I will fight tooth and nail to be on the grid in Australia next year," he said.

"But can I guarantee anything? I'm not prepared to discuss that at the moment but for sure I won't go down without a big fight."

Stoddart insisted that even if a deal is not concluded with Cosworth, Minardi would compete in 2005.

"Recent announcements with Cosworth have made it very, very difficult but I can assure you that Minardi will be on the grid in 2005 in Melbourne, even if we have to do it with our own engine," he told Reuters.