Button says qualifying not critical

Button's recent poor qualifying pace, in relation to his championship rivals, has compromised his strong form in the races and has to some extent allowed both his team-mate Rubens Barrichello and Red Bull's Sebastian Vettel to close in on him in the title battle.

But the Briton, who could clinch his first Formula 1 world championship by finishing third or higher at Interlagos on Sunday, admitted that while a strong grid slot remained important to his race strategy his car's established race pace could play into his hands on a circuit renowned for overtaking opportunities.

"Qualifying is important for a race weekend, but here you can overtake - it is a lot easier than some of the circuits we've been to - but I want to qualify as high up as I can," said Button.

"I think the car can be competitive. On long run pace it is good, which is obviously the race work. You still don't know how quick people are but the feeling of the car is good, and that is important."

Button admitted that he still needed to find a balance with the Brawn over one lap and that he had not yet found a way to unlock the potential of the option tyre, but remained optimistic of doing so in Saturday's final practice session.

"On one lap, I haven't got a balance yet," he said. "I think Rubens is a bit better but I think even for Rubens he has some work to do to improve the car, so hopefully we can do that tomorrow morning. That is more when you work on the qualifying aspect of the weekend.

"But I've got a lot of different things to try tomorrow and I look forward to improving the car.

"We were good on the prime tyre. I was very happy with the balance on the long runs. We did a lot of laps today considering we thought it was going to rain and we wouldn't get much set-up work done. So the prime tyre looks good. We just haven't got a balance on the softer tyre yet and struggled on the new tyres this afternoon.

"It is just such a different tyre to the prime tyre. We haven't got a balance on it and need to work on it overnight."

Button re-iterated his calm approach to what could be the biggest weekend of his career, pointing out that the emphasis was on his rivals to reduce his 15-point advantage, and thus the need for a strong result was more critical to them: "It is a lot easier for me - I am a lot more relaxed than I have been in the last few races.

"I think for Rubens - I wouldn't say it is pressure because people use that word all the time and it is frustrating to hear it - but it is a big race for him. It's his home race.

"For me, I am very relaxed and it is a different situation because Rubens and Sebastian have to beat me by a certain amount of points to stay in the championship. So I should be relaxed."

Button even suggested that he hadn't ruled out chasing a victory, even though third place would be enough to take the world championship.

"A podium would be great - but I am not going to come here to finish third. I want to do the best job I can, which is obviously to challenge for the win," he said.

"You have to say that the most competitive teams are the McLarens, the Red Bulls and us at the moment - and maybe with the Ferrari being competitive also and perhaps the Williams. We'll have to see on that, but for sure the McLarens and the Red Bulls are very competitive."