Why Piastri was handed a time penalty in F1's British Grand Prix

The FIA race stewards have explained why McLaren driver Oscar Piastri was handed a race-altering 10-second penalty for his safety car infringement during Formula 1's British Grand Prix.

Coming to a safety car restart on lap 21 of 52 during a chaotic, mixed weather race, long-time leader Piastri jumped on the brakes down Hangar Straight just as the lights went out on the safety car, signalling a restart for the next lap.

Second-placed Max Verstappen had to brake and take avoiding action in response, momentarily passing Piastri on the right and uttering his displeasure at the championship leader’s actions.

The incident drew some parallels with George Russell being protested by Red Bull in Canada for a somewhat comparable incident behind the safety car, although in Russell's case the stewards agreed his braking was much less severe and in line with normal driving behaviour behind the safety car to heat up the tyres.

However, the Silverstone stewards felt Piastri had clearly crossed the line due to the harsh manner in which he braked, noting 59.2 psi of brake pressure that slowed his McLaren down from 218km/h to 52km/h. They deemed that to be erratic and therefore no longer in compliance with the sporting regulations.

"When the clerk of the course had declared that the safety car was coming in that lap and the lights were extinguished, Car 81 suddenly braked hard (59.2 psi of brake pressure) and reduced speed in the middle of the straight between T14 and T15, from 218 kph to 52 kph, resulting in Car 1 having to take evasive action to avoid a collision," the FIA stewards wrote.

Oscar Piastri, McLaren

Photo by: Zak Mauger / LAT Images via Getty Images

"This momentarily resulted in Car 1 unavoidably overtaking Car 81, a position which he gave back immediately. Article 55.15 of the FIA Sporting Regulations required Car 81 to proceed at a pace which involved no erratic braking nor any other manoeuvre which is likely to endanger other drivers from the point at which the lights on the safety car are turned off.

"What Car 81 did was clearly a breach of that article. In accordance with the penalty guidelines, we imposed a 10 second time penalty to Car 81."

Piastri was furious with his penalty, which he sat out at the final round of pitstops and allowed team-mate Lando Norris to snatch away the win, on home soil.

"Apparently you can't brake behind the safety car anymore," he fumed. "I mean, I did it for five laps before that. I'm not going to say too much, because I'll get myself in trouble."

Piastri finished second behind Norris as his championship lead over his McLaren team-mate shrank to just eight points.