Button fears for championship lead

The Briton had hoped that the tight Hungaroring track and the warm weather of the weekend would help him fight back against the resurgent Red Bull Racing outfit, but tyre woes again left him on the back foot and he struggled home seventh.

And with Mark Webber taking third place to cut into Brawn's ever decreasing championship advantage, Button is now very worried about the state of affairs.

When asked by AUTOSPORT if his 18.5 points advantage was comfortable, Button said: "For sure, not. I have lost 15 points to Webber over the past three races, and that is massive.

"It's five points per race. It means he will be in front of me in four races time, and there are seven races left. So it is for sure not comfortable, but I cannot do anything about it at the moment except we just need to go through the data, which is annoying as we have to wait for two weeks [because of the factory shutdown]."

He added: "We have to sort it out because we are leading the championship, but it is inevitable they are going to overtake us if the Brawns keep going like they are. It is like wearing the yellow jersey [in the Tour de France], knowing that when you get to the mountains you are going to be useless and overtaken.

"It is nice leading the championship, but it won't be the case in the next three or four races if we have the performances like we have had in the last few.

"Valencia I say is going to be hot, but then here we thought it would be in the 30s. But if you look at the weather forecast, it has been 34-35C all week, and the weekend was 24-25C and then it is going back up again from Monday. So, maybe someone is trying to make the racing more interesting this year - they don't want us walking away with it. So they are doing their job very well."

Button says his team has no answers at the moment as to why its early season dominance has come to a halt - but he has faith that the team will come up with the answers he needs to keep his title challenge on course.

"They have done great things with this car, and all through the first part of the season we've added updates and it has improved the car," explained Button. "We've made steps forward and we saw that in Barcelona. And the last two updates, I can't see them as worse. It is not something that would unsettle the car. It should just give the car more downforce.

"It should work in every condition. It is rear downforce. It works. It helps. So there is something not quite right. We are running at 60C with the tyres, which is out of their working range. But how do we get them in their working range? That is what we need to work out."