McLaren team boss Martin Whitmarsh insisted that the F1 title fight isn't over despite Lewis Hamilton losing ground with his retirement in Singapore.

Hamilton was on course for victory when a gearbox issue forced him into retirement and it means he is now 52 points behind Fernando Alonso with 150 still to play for in the final six races of the year.

The Singapore retirement marked the second straight race in which McLaren has lost a car to a mechanical issue and Whitmarsh admitted it was important for the team to try and bounce back from its latest disappointment.

"Reliability, performance, eliminating mistakes, all those things are important," Whitmarsh told the Press Association. "We're inevitably disappointed with what has happened. At the moment it feels tough, but these things happen.

"We're a strong team, Lewis is showing great character, and we'll focus on the six remaining races and see if we can win them. We'll keep pushing."

Whitmarsh added that he still believed that Hamilton could be champion this year and said McLaren wouldn't give up in the race for the crown.

"The situation is obviously a lot tougher now, but we're not giving up, and certainly Lewis is not giving up because it's still doable," he said. "A lot of things can still happen in this championship, and as I've said all along it's going to be determined in Brazil I believe, and therefore we have to keep pushing.

"It's our job now to look it and say 'There are six races, Lewis can score 150 points, so they (Ferrari and Alonso) have to score 100. It is still quite a lot of points, so there's a long way to go yet."