MOTOR SPORT CHINESE FORMULA ONE GRAND PRIX PREVIEW:ON A DAY when he again topped the timesheets, Formula One championship leader Jenson Button has become embroiled in a slanging match with Renault boss Flavio Briatore in the wake of the FIA's midweek ruling that the controversial diffusers of Button's Brawn GP car are legal.

Ahead of tomorrow’s Chinese Grand Prix, Button lapped the Shanghai circuit in a table-topping one minute 36.679, almost half a second clear of the nearest non-double diffuser equipped car, the Red Bull Racing of Mark Webber. That lap time, though, followed a stinging attack from Renault boss Briatore who, in an interview with Italian daily Gazzetta dello Sport, had called the British driver “a paracarro”, a term meaning a roadside bollard.

“Our drivers are, or have been, world champions,” Briatore was quoted as saying in reference to the drivers of Renault and Ferrari, two of the teams that protested the rear diffusers of Brawn, Williams and Toyota. “And then you have a (Brawn GP) driver who was almost retired (Rubens Barrichello), and another who is a ‘paracarro’ fighting for the championship.

“I don’t know how we can say we have credibility, it is impossible to recover the ground we have lost on those teams,” the Italian added.

“In three or four races the championship will be decided, and I don’t know what the interest of the TV viewers will be when Button has 60 points and (Williams’ Kazuki) Nakajima (has) 50. It will be better to listen only on the radio and watch something else.”

Button yesterday responded that Briatore was obviously bitter over Wednesday’s decision by the FIA and that the Renault boss should remember he tried to hire him for own team this season. “Unless he is at the front of F1, I am sure he thinks any team being there hurts the credibility of F1,” Button said. “He is obviously a very angry man after the diffuser issues and he is obviously very disappointed they haven’t produced a car that is as competitive as ours.

“We have produced a very competitive car because of the work-force we have back at Brackely. They have worked very, very hard in very difficult circumstances and it is very, very unfair for Flavio to comment as he has just because he is a little bit bitter – he should also not forget he tried to employ me for this season.”

Indeed, Briatore has already employed Button once, the British driver racing for the Briatore-run Benetton in 2001 and again the following season when Benetton became Renault.

Button’s team-mate Barrichello also weighed in to the argument: “Really. What a comment. If we all think that we need Ferrari and McLaren to win, why are the others here? There are plenty of good people in the paddock and plenty of bad losers.”

Button had the final word, insisting: “It is not our fault we have built a good car, and when a regulation changes I think things change in F1. We have seen change. Some people might not be that happy about it, but instead of getting angry and putting their views out there, they need to concentrate on improving and catching us up.”

That though is easier said than done. Renault’s double world champion Fernando Alonso was left languishing in 19th place after the opening free practice sessions with team-mate Nelson Piquet marginally better off in 16th.

Defending team champions Ferrari, similarly hamstrung by a lack of the clever pieces of engineering which has defined the opening two races of the season, were only slightly further up the rankings, with 2009 title runner-up Felipe Massa in 12th with 2008 champion Kimi Raikkonen two places further back, results that left team principal Stefano Domenicali to comment: “We are in a difficult situation and we must try and stay calm and work hard on all fronts.”

The team has this weekend abandoned the KERS system which adds up to 80 extra horsepower in short bursts during a lap after encountering problems in Malaysia and Domenicali admitted this was also hampering performance “Clearly, without KERS, we lose a bit of performance and initial indications are we are not seeing any improvement in the balance of a car that, let’s not forget, was designed to carry this system. We will have to run a few races on the defensive and try and do the best we can.”

So far it is only Red Bull Racing that has given the “diffuser three” any competition and yesterday the team’s drivers, Mark Webber and Sebastian Vettel, slotted into fourth and fifth respectively, with the Brawn of Barrichello ahead in third, the Williams of Nico Rosberg second.