His Brawn GP began the season with the controversial ’double-decker’ diffuser that has helped Button to victories in Australia and Malaysia.

The FIA’s International Court of Appeal on Wednesday ruled that the component is legal, leaving Renault and six other teams playing catch up to the ’diffuser three’ – Brawn, Toyota and Williams.

That prompted Briatore to issue a damning attack on the decision in a interview with Italian newspaper La Gazzetta dello Sport, in which he said: “Our (McLaren, Ferrari and Renault) drivers are or have been world champions.

“Then you have a (Brawn GP) driver who was almost retired, and another who is a ’paracarro’ (an Italian term for a concrete roadside post), fighting for the championship.”

But Button branded Briatore “bitter” and suggested the Italian should concentrate on improving his own team’s car.

“It is very unfair for Flavio to comment as he has just because he is very bitter,” said the 29-year-old.

“He should also not forget that he tried to employ me for this season.

“He is obviously a very angry man after the diffuser issues and is very disappointed they have not produced a car that is as competitive as ours.

“We have produced as competitive a car as we have because of the workforce back in Brackley and you cannot take that away from them.

“It is unfair to say that as they have worked very, very hard in difficult circumstances.”

The row also prompted a response from Formula One supremo Bernie Ecclestone, who suggested Briatore should concentrate solely on race matters.

“Its a pity they don’t talk more about racing than politics,” he said. “We seem to have got a lot of team managers who’ve become politicians.”

But despite the off-circuit distractions, Button remains focused on continuing his dream start to the season with a victory in Shanghai.

After finishing behind fellow Brit and current world champion Lewis Hamilton in this morning’s practice, Button was on top in the afternoon session.

A win this weekend would add to what is already his best season in Formula One but despite a couple of frustrating years where he has predominantly toiled at the back of the grid, Button insists his passion for the sport has never wavered.

“Just because you have had a couple of bad seasons it does not mean you have lost your love or passion for the sport,” he added.

“We have finally produced a car that is competitive and we are getting the best out of it. It is not our fault that we have a good car.

“Things change in Formula One and we have seen change. Some people might not be happy about it but instead of getting angry they should concentrate on improving and catching us up.”