By Andrew Benson
BBC Sport at Silverstone
Formula One will fracture into two rival series unless Max Mosley steps down as president of motorsport's governing body the FIA.
That is according to Minardi team boss Paul Stoddart, who is acting as spokesman for the rival camp in F1's political dispute.
He told BBC Sport: "If Mosley stays in F1, there will be two series in 2008."
"There will be no unification under Mosley. It's not possible, the damage is too great."
Stoddart said that a split would be a "disaster" for F1.
He likened it to the split between Champ Cars and the Indy Racing League in the USA, which has affected the profile of both championships.
But Stoddart said the rows in the sport had gone on so long that there was no way back while Mosley was in charge.
On one side of the split are Mosley and Ferrari, who are championing a low-tech vision for the future of the sport.
On the other are car manufacturers BMW, Mercedes, Renault, Honda and Toyota and seven of F1's other nine teams.
Red Bull and Jordan have yet to pledge their allegiance.
Stoddart pointed to the fiasco at the US Grand Prix as evidence that there was no prospect of an accommodation between the two camps.
Seven teams withdrew from the US race because Michelin could not guarantee the safety of its tyres.
Mosley rejected a compromise plan that would have seen the race go ahead with the addition of a chicane to the Indianapolis track.
"We've tried so hard to work with Max, and if you ever wanted a clear demonstration that it will never work, you got it at Indianapolis," Stoddart said.
The manufacturer-led group say they want stable regulations and "fair and independent governance".
Mosley rejects accusations that the FIA under his stewardship is not impartial, and denied accusations of major divisions within F1 and that his relationship with the drivers was damaged.
In a press briefing at Silverstone on Friday, he also claimed it would be impossible for disaffected teams to find a suitable candidate to run against him as FIA head by October's deadline.
Mosley told journalists he had wanted to quit to do something else but was now determined to stay on and see things through.
He added: "If I wanted to come down heavy on Paul Stoddart he'd be under 8ft of gravel by now. He needs to lie down in a darkened room and take his medicine."