SILVERSTONE, England (AFP) - Drivers world championship leader Briton Jenson Button blamed lack of grip in the cold conditions for his worst qualifying performance this year on Saturday.

The 29-year-old Englishman, who leads the title race by 26 points after winning six of this year's seven races to date, wound up sixth on the grid for Sunday's British Grand Prix.

Button said: "I don't know if they wanted to save more fuel for the race or what...

"I have driven around this circuit a lot less than the people in front of me. Rubens is very quick here, he always has been. But today I just couldn't find the grip on the car so we're down in sixth.

"We've just got to hope that we've got the right amount of fuel on board; well, enough, compared to the guys in front and we can have a good race.

"I really struggled with the car here, I don't know why it feels like a different car to drive than the one I had in Turkey.

"We knew as soon as we arrived here that the Red Bulls were very quick, but compared to Rubens, who's in the same car as me, it wasn't quick.

"I think if we had got the last lap in, which we should have, I probably would have been three-tenths off them anyway so...

"I just couldn't find the balance in qualifying, especially with the higher fuel I just had no balance which is quite unusual.

"I'm on the third row which isn't great. We've just got to hope that our strategy is better than the cars in front and the cars around us because, when you're in the pack, pit-stops are very important.

"I don't know when the people in front are stopping, I obviously know when Rubens is stopping, but the other guys I don't know. It's going to be a tough day tomorrow and I'm just going to try and manage points and get as many points as I can tomorrow and not make any mistakes.

"The whole lap I'm struggling for grip. It just feels like the whole car is rolling and the car's just not digging into the circuit. Some of it is the temperature - our car works very well when we can get the tyre temperature and we struggle in this temperature.

"But Rubens did a good job and he was second on the grid and we should be judging ourselves against that - and we weren't quick enough, we were about three-tenths off him."