Ferrari has too much power, says Head

Williams was forced to change its rear diffuser in the week after the Spanish Grand Prix after motorsport's governing body the FIA deemed it did not conform to the spirit of the rules. The aerodynamic device is believed to have been investigated following a complaint from Ferrari.

"Ferrari were saying that if they made that same interpretation they could make their car whole seconds a lap quicker," said Head, "which is absolute nonsense. They were scaremongering.

"It seems Ferrari has the inside line on influence in terms of rulings. And it's not surprising they are viewed with some distance by other teams."

However, Ferrari itself was forced to change its rear suspension for last weekend's Austrian Grand Prix, after Williams asked the FIA for a rule clarification. The Italian team was using wishbones that were in the shape of small wings, thought to be outside the spirit of the rules.

"For the first four races of this year Ferrari ran a wishbone aero solution that all the other teams considered illegal," said Head. "Complaints were made and they've changed it."

Eponymous team boss Sir Frank Williams agrees with Head and says his team may have been able to continue with its diffuser had the FIA not been asked to take a closer look.

"Any regulation has loopholes," Williams told Autosport's sister title Motorsport News. "So our engineers spend a lot of time trying to see how to win an advantage.

"On the diffuser we thought of something we thought was permissible, ran it by [FIA technical delegate] Charlie Whiting and he said fine. But because a certain amount of pressure arrived from other teams, the FIA decided to close up the loophole."