From GMM

Jenson Button is still at stalemate with his boss Ross Brawn, who has hinted the Englishman might have to leave the team as world champion.

29-year-old Button is locked in stalling negotiations to increase his retainer for 2010 from a cut-price $5m.

He agreed to slash his contracted pay for 2009 in order to aid the management buyout, and has also been paying his own way in terms of hotel and travel expenses.

But Button's manager Richard Goddard told the Daily Star Sunday that he is "shocked" Brawn is refusing to offer anything more than a slight pay rise.

"We aren't being greedy," he said. "When we signed the deal last year, we did so in the knowledge that if all went well for the team, things would also go well for Jenson."

Team owner and boss Brawn hinted that the impasse could lead to Button leaving the team after November's Abu Dhabi GP.

"Those decisions have not yet been made but if we have a world champion who, for whatever reason, leaves the team, that's a shame," said the Briton.

Brawn's reluctance to offer Button much more money could be related to the paddock perception that - according to former racer Martin Brundle - the British driver is now "reversing" his way to the title after a strong start to the season.

Meanwhile, Heikki Kovalainen could retain his McLaren seat in 2010, team boss Martin Whitmarsh admitted to reporters in the Suzuka paddock.

The British team has been contemplating a new teammate for Lewis Hamilton, and in recent days the link with a return to McLaren for Kimi Raikkonen has strengthened.

Whitmarsh said in Japan that the current Ferrari driver is one option for 2010, but insisted that McLaren's current Finn is not yet out of the running.

"We are not waiting for Kimi," the Briton said. "There's a very good possibility that Heikki will be driving for the team again next year."

Hamilton, managed by his father Anthony, has suggested publicly on a number of occasions that he would like to keep Kovalainen as his teammate.