Singapore - Force India team principal Otmar Szafnauer has read the riot act to Sergio Perez, describing his erratic performance at the Singapore Grand Prix as "unacceptable" after the Mexican pushed his team-mate Estaban Ocon into the wall on the opening lap.
Perez ended the Frenchman's race after just three corners, held up Ferrari's Sebastian Vettel and had another collision with Sergey Sorotkin's Williams before he eventually crossed the line in 16th place after an eventful grand prix.
"You say to them that's unacceptable, there's enough room on the left hand side as I could see. You've got to give your team-mate enough room," an angry Szafnauer told reporters.
"If it's somebody else and it's not your team-mate, it's a racing incident. But if it's your team-mate then you've got to give him room.
"So we're back to the old rules, we allowed them to race on lap one whereas in the past we didn't allow them to race on lap one and now we can remove that.