The Grand Prix Drivers' Association gave Formula One's organisers an uncompromising ultimatum last night that they will not race the German Grand Prix if there are any signs of further problems with Pirelli's tyres this weekend.
After a meeting at the Nürburgring, the GPDA expressed their "deepest concern" over the events in the British Grand Prix at Silverstone last week, in which four drivers suffered explosive tyre failures.
"We trust that the changes made to the tyres will have the desired results and that similar problems will not occur during the German GP weekend," a GPDA statement said. "We are ready to drive our cars to the limit as we always do, and as it is expected by our teams, sponsors and fans. However, the drivers have decided that if similar problems should manifest themselves during the German GP, we shall immediately withdraw from the event as this avoidable problem with the tyres endangers again the lives of drivers, marshals and fans."
Pirelli has suggested after analysis of the problems at Silverstone that some teams had been running uni-directional tyres the wrong way round, and at excessively steep camber angles and low pressures. But this week's medium- and soft-compound tyres will feature a Kevlar belt in place of a steel belt to add strength, and a new tyre is due for the Hungarian GP at the end of the month.
The last occasion drivers withdrew was ahead of the 2005 United States Grand Prix at Indianapolis over concerns about the Michelin tyres on 16 of the cars.
"After what we saw in Silverstone, we now go to the Nürburgring confident we can see an improvement," Ferrari's Fernando Alonso had said earlier. "I know that various modifications have been applied and let's hope that means all of us drivers can race in safe conditions. At the moment, we can't make any predictions, because no one has tried them and we don't know what and how many benefits they can bring, apart from trusting in the fact that it won't be dangerous to race."
"I think it's definitely important to change the tyres for the safety, and very important that we as drivers are safe," said McLaren's Sergio Perez. "Something bad could have happened at Silverstone, but Pirelli have acted very fast."
However, the mood among the drivers hardened after the meeting. "We don't want to boycott," a GPDA representative said last night. "We truly believe the changes made by Pirelli will make the tyres safe. We only want to make clear our position if there are more blow-outs. Safety first."
Lewis Hamilton seemed less concerned despite being the driver who lost most from a puncture at Silverstone. The Brition said: "I haven't thought about the tyres. I just hope that our car is as strong here as it was last weekend. But I'm guessing there also might be some luck involved in getting the new tyres to work the same way. It might reset the championship fight, but I don't see any point in worrying about that right now."