Ferrari president Luca di Montezemolo said on Wednesday that Max Mosley should quit as chief of motor racing's world governing body over his involvement in a sex scandal.
"I think that he should realize that sometimes it is necessary to say to yourself I have to leave for reasons of credibility," Montezemolo told the ANSA news agency.
Mosley was given a strong vote of confidence to remain as president on Tuesday, gaining 103 votes to 55 against in a secret ballot at an extraordinary meeting of the International Automobile Federation (FIA) general assembly in Paris.
The 68-year-old Briton has ignored calls to quit since March when the tabloid News of the World newspaper published details and photographs of his involvement in what was described as a Nazi-style sado-masochistic orgy with prostitutes.
The FIA president, whose father Oswald was the founder of the pre-World War Two British Union of Fascists, has denied any Nazi connotations to the scandal and is taking legal action against the News of the World for invasion of privacy.