SILVERSTONE, England -- Formula One world champion Jenson Button branded his McLaren "undriveable" on Saturday after qualifying in 14th for the British Grand Prix.
After McLaren engineers abandoned the team's ineffective aerodynamic upgrades following sluggish practice sessions on Friday, Button had anticipated a better performance at Silverstone.
But the 30-year-old Button struggled with downforce and now looks set to miss out on a podium finish at his home race for an 11th consecutive race.
"This morning [in the final practice session] the car felt really good but the car was undriveable this afternoon," Button said. "As soon as I jumped in it. I took so much front end out of the car.
"I don't know if I have lost rear downforce since this morning but it is pretty undriveable. It hasn't got the blown diffuser. This weekend, it has been tricky for us, but that wasn't normal."
The exhaust blown diffuser was abandoned after causing the bodywork of the McLarens to overheat and disturbing the balance of the car.
"There's a lot of work to be done on the upgrades to improve them -- it wouldn't have been right to run them here," Button said.
The new front wing was one of only a handful of the original 20 enhancements that were retained.
Button's teammate Lewis Hamilton managed to qualify in fourth despite the problems.
"I honestly feel it was the best lap I've done since I've been in Formula One," said Hamilton, the 2008 world champion. "Bit by bit I've adjusted the car, and although it wasn't perfect, I've really strangled its neck and pulled out every little bit."
The McLaren duo top the drivers' championship ahead of the Red Bull drivers, who have been using the diffuser with positive results this year.
Red Bull's Sebastian Vettel, who is on pole for Sunday's race, won in Valencia two weeks ago to close the gap with championship leader Hamilton to 12 points. Vettel, who has 115 points, is six behind Button.