Formula One championship leader Jenson Button hit back at a jibe from Flavio Briatore about his driving today, saying the Renault boss had tried to hire him for this season.

Briatore told Italian media the decision to declare legal the rear diffuser used by Button's Brawn GP car had as good as decided the title, adding that the Briton was "as quick as a milestone". "It hurts the credibility of Formula One. He also needs to remember that he tried to employ me for this year." the 29-year-old Button, who has won the first two races of the season, told reporters at the Chinese Grand Prix.

"He's obviously a very angry man after the diffuser issues, he's obviously very disappointed that he hasn't produced a car that's as competitive as ours.

"We've produced a very competitive car because of the workforce we've got... and you can't take that away from them."

Brawn GP was formed after a management buyout of the Honda team after the Japanese car manufacturer decided not to continue in Formula One, and for a while it was by no means certain they would line up to race this season.

Since the start of Winter testing, however, they have had the quickest car on the track and the governing FIA's decision on Wednesday to dismiss an appeal from Renault and others against the use of the diffuser has made then clear title favourites.

Briatore said making up the technical gap with the teams with diffusers was "impossible" and also suggested the credibility of the sport would suffer.

"It's unfair to say that, (the team) worked very, very hard in difficult circumstances," added Button, who set the quickest time in today's two practice sessions.

"It's very unfair for Flavio to have commented as he has just because he's a little bit bitter.

"When regulations change, Formula One changes and people are getting angry and putting their views out there when they should be concentrating on catching us up."