Lewis Hamilton has claimed there are “no rules” at Ferrari after a first-lap clash with teammate Charles Leclerc sent him onto the gravel during the Italian Grand Prix.

Hamilton moved alongside Leclerc into the opening chicane, but the pair ran out of space through the second part of the corner, forcing Hamilton onto the gravel and dropping him down the order.

Leclerc later crashed out on the second lap after losing control at the Parabolica, bringing out a red flag, while Hamilton recovered to finish sixth.

Hamilton said Ferrari needed written “rules of engagement” governing how its drivers race each other, pointing to his previous experience at Mercedes.

“When I was at Mercedes, we had a written rule of engagement,” Hamilton said. “Here, there are no rules.”

The seven-time world champion rejected Leclerc’s suggestion that both drivers were responsible for the incident, insisting he was ahead at the second turn.

“I was ahead in Turn 2. By the apex, I was ahead. There was no ‘we’ in it,” Hamilton said.

Leclerc described the battle as “way too close” and said he was unsure whether the two cars had made contact.

Hamilton’s sixth-place finish left him 76 points behind championship leader Kimi Antonelli, who won the race from 19th on the grid.

The result also proved costly for Ferrari at its home race, with Leclerc failing to finish and the team losing further ground to Mercedes in the constructors’ championship.