Flexi saga has slowed Red Bull down - Button

The flexible cars controversy slowed down the previously dominant Red Bull team at Spa-Francorchamps, according to Jenson Button.

Although the Austrian owned team claims the long straights of the Belgian circuit simply did not suit the RB6, McLaren's Button suspects Adrian Newey had to modify the car to meet more stringent bodywork flexibility tests.

Button's boss Martin Whitmarsh, and Mercedes' Ross Brawn, said last weekend that they thought the front wings on the Red Bull and Ferrari cars were flexing less visibly than they had in Hungary earlier in August.

"I think Red Bull's pace was affected by the new tests," said the reigning world champion.

"I hope the new even more stringent tests for Monza will have even more of an effect. They say they won't have to change anything but they said that here.

"Watching the car here on the track it was not flexing as much," added Button.

The 30-year-old also does not expect Red Bull to obtain a championship advantage by appointing Mark Webber as the number one driver for the rest of the 2010 campaign.

"I don't think they will. I think they love Vettel," he said.

McLaren team boss Whitmarsh added: "I think (Red Bull) quite like their younger driver, so I doubt they will put their weight behind Mark."