On the day of the British Grand Prix, F1 hits the buffers

As breakaway grows, ex-champion Jackie Stewart tells FIA president Max Mosley that it's time to go

As civil war broke out in Formula One at what is scheduled to be the last British Grand Prix held at Silverstone – with the major teams announcing their intention to run their own breakaway series in 2010 and FIA president Max Mosley threatening legal action against them – Sir Jackie Stewart applauded the renegades and renewed a call for Mr Mosley to resign.

The eight rebel teams, which include Ferrari, Renault and McLaren, appeared undeterred by FIA threats of legal action and invited other teams to help to expand their plans for a brand new championship.

As teams prepared for today's British F1 championship race, Martin Whitmarsh, head of McLaren, Lewis Hamilton's team, said the FOTA (Formula One Teams Association) had enough teams to implement the split. "We would welcome any new teams, or existing teams for that matter," he said.

Mr Mosley continued to insist the threats were all "posturing and posing" and that there was a personal campaign against him, but yesterday drivers were questioning the future. Former champions Fernando Alonso and Michael Schumacher hinted the breakaway would be what motorsport fans would want to see.

Sir Jackie, a three-time world champion, said: "The manner in which the FIA is being managed is completely contrary to the scale and importance of F1. In a statement this morning Max Mosley described the FOTA teams as loonies and when asked who he thought was their leader replied, 'Loonies don't have leaders, do they?' This is the man responsible for the biggest capital investment sport in the world, speaking so frivolously. It shows no good judgement."

Sir Jackie also said that he wished the negotiations with the teams had been conducted instead by the sport's commercial rights holder, Bernie Ecclestone. "If that had been the case we would have seen a deal done. Bernie would have seen the absolute necessity to do that. Bernie is not being very vocal but he is saying to lots of people that Mosley has got to go, though I don't know if he means that."

Sir Jackie and Mr Mosley have long locked horns, not least after the McLaren spy scandal in 2007 and Mr Mosley's prostitute sex orgy last year. Mr Mosley in the past has dismissed the Scot, who is hugely respected within the sport, as a "certifiable halfwit".

"Mosley fined McLaren $100m in 2007 for something that was never proven. Think about that. That's way more than BP were fined for the refinery explosion in Texas that killed people. How can the FIA justify that?

"I believe that a deal was done under the counter to oust McLaren chief Ron Dennis this year, and that a condition of McLaren's suspended sentence after the Malaysian race for lying to the stewards in Australia was that Ron got taken out. Hang on a second, that is just not allowed. How is that a way to govern a sport? You would never see that at Wimbledon or in golf."

Mr Mosley said: "Always with these things in the end there is a compromise because they can't afford not to run in the Formula One world championship, and we would be very reluctant to have that without them."