Formula One has been threatened with a boycott of this weekend's German Grand Prix.
The shock message has come from the Grand Prix Drivers' Association, and in the wake of Sunday's scenes at the British Grand Prix where a number of blowouts overshadowed the race.
For this weekend, the belt on the rear tyres is now made of Kevlar -- a high-strength synthetic fibre which is more resistant to punctures -- as opposed to the steel that was previously used..
Earlier yesterday, in the paddock at the Nurburgring, the message from the drivers was predominantly positive, with many praising Pirelli for the speed of their response. But following a meeting of the GPDA -- chaired by Pedro de la Rosa and with Sebastian Vettel and Jenson Button as directors -- it has now emerged the drivers are more than willing to not drive should there be a repeat of the scenes at Silverstone.
A statement read: "The drivers of the Grand Prix Drivers' Association wish to express their deepest concerns about the events that took place at Silverstone.
"We trust the changes made to the tyres will have the desired results and that similar problems will not occur during the German GP weekend. 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 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."