Most current Formula One teams are unlikely to submit entries for next year's championship by a 29 May deadline, commercial supremo Bernie Ecclestone said today.
"We'll have to wait and see. I think the majority probably won't put an entry in," he told Reuters at the Monaco Grand Prix.
Toyota, champions Ferrari, Renault and the two Red Bull teams have all threatened to walk away unless the 2010 regulations, which include an optional £40m budget cap, are rewritten.
Ecclestone doubted there would be any easy solution to a crisis that threatens to tear the sport apart and Toyota motorsport director John Howett said his team could not enter until a number of issues had been resolved.
"There is a high probability that we won't enter before the deadline because I don't think that those items will be clarified," he told Reuters.
"If nothing changes I don't think that professionally it is possible to commit the company to do that. I can't recommend that in my position."
Although FIA president Max Mosley and Ecclestone have said they expect all teams to compete under the same regulations, the cap would give those teams accepting it greater technical freedom than others remaining on unrestricted budgets.
Ferrari say the budget cap and the sort of new entrants attracted by it would reduce Formula One, the pinnacle of motorsport, to the level of a junior series.
The Italian glamour team failed to secure an injunction in a French court on Wednesday to stop the FIA introducing the changes.
Ecclestone said the situation worried him.
"We don't want to lose Ferrari," he said. "I hope it's unlikely. I am concerned, I don't want them leaving. I don't think anybody does."
Howett said Toyota needed guarantees.
"With the investment we have and the social responsibility, we need at least a three year vision of what we are participating in and what the future is and how it can be redefined," he added.
"At the moment it is too uncertain."
The Formula One Teams Association (FOTA), of which Howett is vice-chairman, will meet in Monaco on Friday to discuss the situation after a meeting with Mosley in London last week ended in stalemate.
"Governance (for Toyota) is a fundamental issue and for us that's a principle that needs to be clarified before we can actually talk about the detail," said Howett.
"The danger we had in the meeting (with Mosley) was being sucked into the detail."
Howett said there had been an unsuccessful attempt to stage a walkout by teams from that Heathrow meeting, with some standing up to leave while others remained seated.
"We need to just understand clearly among the members of FOTA what the clear position is," he said.
"We need a tri-partite Concorde Agreement where it is absolutely clear how the regulatory framework can be changed. it's very simple.
"I don't think we want to actually dictate the rules but those rules must be changed in compliance with a fixed structure which is legally binding. At the moment that is not the case."