Formula One drivers could go on strike if their safety concerns are ignored, Briton David Coulthard warned on Saturday.
"Strike action could hit the second half of our season," the Red Bull driver said in a column for Scotland's Daily Record newspaper.
"That's how strongly I and my fellow drivers feel over the safety concerns that have dogged us since last month's U.S. Grand Prix," added the Scot.
Most of the drivers signed a statement after the June 19 race at Indianapolis, supporting the stance of the seven Michelin teams that withdrew before the start because of fears about the safety of their tyres.
Just six cars took part in that race at Indianapolis after requests for a temporary chicane to be inserted before the final banked corner were rejected.
The drivers also expressed concern at proposals put forward at the time by the governing International Automobile Federation (FIA) that the Michelin teams use the pitlane to avoid the corner or reduce their speed.
FIA president Max Mosley called off a meeting with the drivers before last weekend's British Grand Prix because of comments Coulthard made about the regulations.
That meeting has been rescheduled for August 1 in the south of France -- providing at least half of the super licence holders are able to attend.
Coulthard said that some, such as BAR's Japanese Takuma Sato, had already said they could not.
The drivers want the FIA to ensure safety measures at private tests are on a par with those at grands prix and have also expressed concern about the handling of the U.S. Grand Prix.
"I hope the meeting goes ahead," said Coulthard. "We want to ensure safety is the priority. It is entirely possible we could strike if we are forced to do something we don't feel is safe.
"Hopefully that won't happen but if need be we will stick together and walk out. What happened at Indy has given everyone a shake."