In his opening speech at today's International court of Appeal, Ferrari's lawyer accused Ross Brawn of being "arrogant".
Nigel Tozzi QC, Ferrari's legal representative, launched a stinging attack on the Englishman, who helped lead the Maranello outfit to countless titles but now runs his own team, which, after just two races, is being tipped for championship glory.
"Only a person of supreme arrogance would think he is right when so many of his esteemed colleagues would disagree," said Tozzi, according to the Press Association.
Referring to the claim by three teams, and upheld by Race Stewards in Australia and Malaysia, that the 'double-decker' diffusers on the Brawn and two other cars are legal, Tozzi continued: "Anyone with a command of English will tell you it is a hole, so do not let someone attempting to be clever with words defeat the express purpose of the rules.
"This appeal is not because we (Ferrari) have not made the most of an opportunity," he continued, "but because Brawn, Toyota and Williams have not acted within the regulations."
However, talking to the BBC, Brawn remained adamant: "You can't be 100 percent confident. But I hope that common sense prevails on our side and the appeal court judges that there is a mechanism, a procedure, a policy and that it was followed properly and we should be left to get on with it.
"We didn't consider this to be a radical new design," he added. "It was an innovative approach of an existing idea, and Formula One is all about innovative design. It's a cornerstone and objective of the sport."