Formula 1 faces continued uncertainty over its exhaust regulations after this morning's meeting of the sport's team bosses and technical chiefs at Silverstone failed to reach an agreement.
Following a weekend of controversy over the FIA's clampdown on the practice of off-throttle exhaust blowing and the various allowances made to engine builders on reliability grounds, the governing body said it would call off the rule tweak and revert to the pre-Silverstone situation if the teams agreed unanimously that this was the best option.
But this morning's meeting saw no unanimous support for such a deal.
AUTOSPORT's sources have revealed that Ferrari and the Ferrari-powered Sauber team refused to sign the deal to return to the Valencia specification.
There had been speculation that Cosworth engine user Williams would do likewise, but it is understood to have been in favour of this solution.
F1 team representatives said they was now unsure where the situation would head now - with the sport bracing itself for further debate in the build-up to the German Grand Prix.
One team boss said: "The situation is now ridiculous. We now don't know what preparations we should make for the next race; or what work we should do with our engines or our exhausts."
McLaren team boss Martin Whitmarsh had said yesterday that revert to the pre-Silverstone situation was in his opinion the only sensible option.
"Inevitably in F1 self interest sometimes prevails, but I think unless we go back to that, then this season is going to be fraught with paranoia, the feeling of being hard done to, being disadvantaged," he said. "We have got what we have got.
"It may be worse for other teams. It has certainly hit this team, it has hit the performance of our car, and I think that is evident from the stop watch - and hopefully from our perspective we get to a situation.
"It is not good to change the rules midway through the year. If you do that, the team that has worked hardest to perhaps refine that particular rule may well be disadvantaged."