By Alan Baldwin
MEXICO CITY (Reuters) - Mercedes bosses criticised Red Bull's Max Verstappen on Sunday after the Dutch teenager banged wheels with Formula One championship leader Nico Rosberg at the start of the Mexican Grand Prix before later aggressive attempts to overtake.
"Nico clearly was in front and Verstappen rams him off the track," non-executive chairman Niki Lauda said of the first corner incident.
"This could have cost Nico the championship. This is not acceptable.
"His talent is unbelievable but then he smashes it all with these stupid actions."
Mercedes motorsport head Toto Wolff said Verstappen's driving was exciting but agreed that the 19-year-old should have shown more respect for a title contender who ultimately finished second and is now 19 points clear with two races remaining.
"I think it’s very refreshing how he drives. His driving is ruthless, I like that," the Austrian told reporters.
"I think that the team gave him a radio call...when he was catching up that said ‘keep it clean with Nico’ and this is exactly what I would have said to him. You don’t bang wheels with the championship leader three races from the end (of the season).
"The team have given him the guidance but maybe in the car when the visor is down it’s different."
Verstappen was also in the spotlight for cutting a corner while defending against Ferrari's Sebastian Vettel, an action for which he was penalised after the finish and demoted from third place to fifth, before being moved up to fourth.
At the finish, he and Vettel engaged in angry hand gestures to one another.
"A repeated offender like him has to be penalised. (Red Bull motorsport consultant) Helmut (Marko) should talk to him," declared Lauda to television reporters.
"If Verstappen wouldn't drive that aggressively, he would develop much better...he doesn't realise. He thinks he is doing everything right but he doesn't. He has to calm down.
"I don't know where this arrogance comes from. I don't understand. This is a lost cause. The fury of the other drivers just gets bigger and bigger."
Rosberg said the duel with Verstappen had been a "bit on the limit" but good racing.
"From in the car, it was pretty exciting stuff and I'm very happy that I managed to come out on top every time and finish second."
(Reporting by Alan Baldwin; Editing by Andrew Both)