FIA boss Max Mosley has seemingly called former triple world champion Jackie Stewart a 'certified halfwit' during a tirade in response to the Scot's criticisms of the £50m fine handed down to McLaren in the wake of the F1 Spying Scandal, The Mail on Sunday website is reporting.

Stewart was one of the most prominent protesting voices over the way the WMSC handled the spying allegations and, following their decision to fine McLaren, declared the sanction 'unjustifiable'.

Mosley responded at a 'media lunch' on Monday: “There's one particular ex-driver who because he never stops talking, never has the chance to listen — so he doesn't know what's going on.

“He said the FIA's decision would not have worked in a civil court. He has no qualification to say that.

“Then he starts saying this is personal between me and Ron Dennis, at great length, because everything he does is at extreme length.

“It's annoying that some of the sponsors listen to him because he's won a few championships. But nobody else in Formula One does — not the teams, not the drivers. He's a figure of fun among drivers."

Presumably referring to the tartan trousers and matching hat Stewart wears to GPs, the President of the FIA added, “He goes round dressed up as a 1930s music hall man. He's a certified halfwit.”

Mosley, who has never made any secret of his desire to see Hamilton and Alonso thrown out of the driver's championship, again claimed that the decision to exclude the team from the Constructors Championship wasn't personal and that he doesn't 'hate' Ron Dennis.

Commenting further on what he thinks of the McLaren boss, Mosley went on to say, "I think what Ron has done is amazing. A lot of people are mechanics but he's the one with probably the best organised F1 team. It's something to be immensely proud of."

Mosley was quick to rebuff the theory that the disagreements between them stem from social, rather than academic issues saying, "Apparently he gets super p*ssed off, with the picture of him as an engineer on Jack Brabham's car. He's much grander than I am. He's a Commander of the British Empire. I'm not even a Member. The sport need characters like him rather than some faceless manager."

Allegations that he is attitude to Scuderia Ferrari is not sufficiently impartial were also, unsurprisingly, rubbished: "If Ferrari's chief designer had 780 pages of McLaren secrets and I didn't act then there might be a point to the argument."