Kiwi Liam Lawson, Max Verstappen cop grid penalties after F1 collision

Kiwi Liam Lawson and Max Verstappen have both copped one-place grid penalties, following what stewards say was an "unacceptable" collision during practice for the Mexican Formula One Grand Prix.

The incident, early in the second practice session, left debris on the track and both drivers blaming each other.

Four-time world champion Red Bull driver Verstappen tried to drive down the inside of Lawson at the Autódromo Hermanos Rodríguez, but the New Zealander held his ground, forcing both cars to be wheel-to-wheel through a tight section.

They ultimately made contact, damaging Verstappen's bargeboards and breaking the front wing of Lawson's Racing Bulls car.

A red flag was deployed to temporarily halt the session while the track was cleared.

After several hours, the stewards' official ruling was that the drivers' behaviour as "unacceptable", adding that both had admitted their moves were "unnecessary and clumsy".

Verstappen heavily criticised Lawson, saying: "Not very smart behaviour, what he was trying to do there... When you're fighting for your seat, it's not very smart behaviour."

Lawson expressed his frustration over the team radio immediately after the impact, saying: "He literally just drove into me. Every weekend he plays this game."

Racing Bulls team principal Alan Permane criticised both drivers.

"I think one word, just 'unnecessary' in a practice session," he said. "Completely unnecessary and I say that to both of them.

"I don't know what Max has said, I haven't heard anything. I'm sure he's got his opinion and I'm sure Liam has got his opinion, but mine is it's just not needed and they can both do better."

Lawson had otherwise made a solid start to the weekend, clocking the ninth-fastest time in the second practice session.

Ferrari's Charles Leclerc was quickest.