Whitmarsh: McLaren cautious but confident

Hamilton is heading into the Interlagos event with a seven points advantage over Felipe Massa in the points standings, which means he only needs to finish fifth to guarantee himself the crown. With a gearbox problem in last year's Brazilian Grand Prix having cost Hamilton the title, however, the team are well aware of the hurdles that need to be overcome before the championship can be won.

And although Whitmarsh concedes the team are anxious about unforeseen situations that can trip them up, he is quietly confident that the Woking-based outfit have done all they can.

"I think if we said that none of us were nervous about reliability then we would not be speaking entirely the truth, because that is a consideration," he told autosport.com when asked about the team's mood ahead of the weekend.

"It is a worry. But whatever happens, we want to be able to look at ourselves on Sunday evening and say we did everything we could - and hopefully have got the right result."

Whitmarsh said that the team have undertaken a great deal of work at the factory to ensure they are as well prepared on the reliability front as possible for events in Brazil. McLaren have already confirmed they are using a new rear wing and other aerodynamic developments this weekend.

"We have meetings before every race," explained Whitmarsh. "We have reviewed any area where we feel we are at risk, and we have put in a tremendous amount of work into the assembly of components, the hydraulic systems and areas like that.

"It has been done to the highest level we can achieve. There is a lot of tension, but we want a straightforward race this weekend with good reliability - and there has been a lot of effort to make that happen.

"At the same time we have put work into the car to improve it as well, so we are not going to just sit back and not push. We have to keep pushing as it is a very competitive season.

"But we don't need to win this race to win the drivers' world championship. A lot of things can happen here. There are some exciting first and second corners, and the weather can play a part as well. So I think it will be a tense afternoon for everyone on Sunday afternoon - and certainly everyone in the McLaren and Ferrari camps."

But although being mindful of unreliability causing the team trouble, Whitmarsh is confident about the team's chances of leaving Brazil with at least one title.

"We have to look at the positives," he said. "We are at the last race, we are a team still fighting for both world championships and most of the teams are not in that position.

"We have two very young racing drivers, who are great team mates, and we feel fantastic as a team. So there are a lot of positive aspects. We have developed the car and managed to do so again for this race, so I am not feeling too downbeat. I think we can leave here with at least one of the world championships, and possibly two."

Whitmarsh has also praised the way Hamilton is approaching the weekend, despite the pressure of the situation.

"He did a fantastic job at the last race, and that is a good way to come into the finale. His confidence and self belief are very high and he is relaxed about all the circumstances. He believes he can get the job done."

McLaren are not alone, however, in ensuring their car is as well prepared as possible. Ferrari broke a seal on Massa's gearbox on Wednesday in order to change the right hand side differential to drive shaft flange seal. This was done in accordance with the technical regulation so there is no penalty.