Sergio Marchionne has sustained his attack on Formula 1 sporting boss Ross Brawn.

At Ferrari's Christmas lunch, the Ferrari president said that he had threatened to pull the Italian marque out of F1 because Brawn is "looking at ways that are against the DNA" of the sport.

Marchionne is now quoted as saying by Speed Week: "I have a good relationship with Chase Carey. We saw each other 10 days ago and we had a very open dialogue.

"What I do not care for is when Ross Brawn comes along and announces that grid girls have to go. And how the engines and chassis should be.

"He behaves like Moses reading the Ten Commandments. And when I call Moses' boss, he tells me that it was just his personal opinion.

"So I don't want to participate in such a discourse. I want to sit down and talk to those involved. It's not helpful to involve the media."

The Ferrari president revealed that engines are currently sold to customers for EUR €15m (£13.3m).

"When I hear Ross Brawn say engines are too complicated, I ask 'What does he want for €15m?'" said Marchionne.

"Liberty Media is right when they say we need to improve the show. I was not excited with what was offered at the last race, where virtually nothing happened for 50 laps.

"But that's not the fault of the engines.

"In an ideal world I would throw all the rules out of the window. Instead, we get suggestions that would lead to all the cars differing only in colour.

"If this is the Formula 1 of the future, then Ferrari will only need three seconds to decide about leaving."

Ferrari finished the 2017 championship in second place, 146 points behind Mercedes.