Horner reckons Button now vulnerable

Button has scored just 11 points in the last five races and, although he still enjoys a 16-point lead over Brawn GP team-mate Rubens Barrichello, there have been concerns that his title charge is running off the rails.

Now Horner, whose drivers Sebastian Vettel and Mark Webber are just a few points adrift of Barrichello, reckons his men can sniff a serious chance of pulling off the championship.

"Both our drivers see he is vulnerable and sense the championship is there to be taken," said Horner ahead of qualifying for the Italian Grand Prix. "Mark and Sebastian are brilliant competitors. Mark has that Australian thing - his confidence is high. The move he did on Jenson in Malaysia was outstanding. Both our drivers are great competitors and very hungry to deliver."

Horner believes Button is suffering from the pressure of leading the championship, and reckons that until the British driver finds answers as to what has gone wrong in recent races he will not be able to relax.

"In the first six races you'd put your money on Jenson for the championship and in the last six Rubens; the tables have turned," he explained. "In the last few races Rubens has extracted more from the car than Jenson. He's got more out of it. He certainly doesn't look like he's attacked the last five races.

"Jenson has tightened up. He's had a stay of execution for the last five races. It can't go on forever, he's been lucky no one has put a run together and taken a big chunk of points out of his lead.

"I have known Jenson since he was 11. He has won a lot of races but not many championships and finds himself in uncharted territory. Unfortunately he's got everything to lose. He is inexperienced at being the favourite.

"Everything that is happening to him must be playing on his mind. It can't not be. I'd be a worried man if I was him. Wouldn't you be? Things have not been going right for him lately. You can see he has tightened up since Turkey. He has not been anywhere near the podium since May and he's probably trying to understand why. Until he answers those questions it's difficult to see a recovery.

"He's scored 11 points since Turkey and before that he was getting 10 points at pretty much every race. That makes a difference to your mental state.

"It's easier to win from the front rather than in the demolition zone. That's where he has been. He needs to find answers. At the moment he is like Stuart Pearce taking a penalty. It's like the top 25 tennis players, they can all play the strokes, but it's who wins the big points. It's the same in any sport."