On the eve of the seventh round of the 2009 Formula 1 World Championship in Istanbul this weekend, early-season runaway pace-setter Jenson Button has defended his Brawn GP team against accusations from rivals that the ex-Honda F1 outfit's superiority has made the top flight boring and rendered the title chase 'already over'.

Ahead of the Turkish Grand Prix around the technically challenging and physically demanding Istanbul Park Circuit close to the Bosphorous - a race in which Button is once again favourite to prevail - the British star holds a 16-point lead in the drivers' standings over team-mate Rubens Barrichello, with the first non-Brawn driver Red Bull Racing's Sebastian Vettel a gaping 28 points adrift in third.

Of the expected contenders for the crown, Renault's Fernando Alonso has just eleven points to his name, defending world champion Lewis Hamilton and 2007 title-winner Kimi Raikkonen are both on only nine, and last year's runner-up Felipe Massa counts a mere eight.

Button's commanding margin is the product of a superb and entirely unheralded start to the campaign for a squad that - only a matter of weeks before the curtain-raising Australian Grand Prix in Melbourne - had looked to be down and out and unlikely to be on the grid at all following parent company Honda's sudden and shock withdrawal at the end of last year.

The performance of the Mercedes-powered BGP 001 has been credited to esteemed F1 engineering guru Ross Brawn, who elected to cease development of last year's unloved RA108 earlier than any other team in order to make sure of getting the 2009 machine - designed to drastically different aerodynamic and technical regulations - absolutely right.

The last time one driver and team dominated proceedings so much was during the Michael Schumacher/Ferrari era that turned swathes of viewers away from the sport, and in a similar display of supremacy, Button has triumphed in five races out of six to-date. Indeed, between them, he and team-mate Barrichello have accounted for nine of the 18 podium places so far - a crushing record by any standards but also, the Frome-born ace argues, a fully deserved one.

"I think that we've achieved a lot this year," the 29-year-old is quoted as having said by The Associated Press. "Us being quick shouldn't be a negative either - we're here to do the best job that we can and that's what we've done. That's what this sport is all about.

"It means a lot beating those teams (like McLaren-Mercedes and Ferrari) - it's what we're all here to do. The way this season has been for us has been fantastic, and I don't think it would be correct if it wasn't the same in the coming years."

Those sentiments are decidedly not shared by either Massa or Alonso, both of whom are seemingly a little miffed that after entering the season expecting to be duelling it out for the crown, they are instead scrapping over the crumbs from Button and Brawn's table.

"It's impossible to believe they are going to lose the championship," Massa argued. "For me, it's already over."

"It's something that this championship with the new rules hasn't achieved this year," added Alonso, evoking campaigns gone-by when it was 'three drivers, three different teams fighting for championship'. "This year it's more a fight between team-mates. This is not good."