All three teams are free to race in the Chinese Grand Prix in Shanghai.

"The decision comes as no great surprise," said BBC Radio 5 Live Formula One commentator David Croft. "Already this season two sets of stewards, an FIA president and an FIA race director have thought that the diffuser design of Brawn, Williams and Toyota was OK.

"It’s a sensible decision for Formula One. The FIA’s court of appeal were highly unlikely, on technical grounds, to go against the decision of the stewards. Seven teams are now playing catch up and have to do something about it very, very quickly."

Brawn GP currently lead the constructors’ world championship with 25 points, with Toyota in second place on 16 points. A Toyota statement issued immediately after the ruling said: "Our team studied the wording of the new 2009 regulations in precise detail to ensure we interpreted them correctly.

"We also made full use of the consultation procedure with the FIA which was a helpful process to ensure our interpretation of the technical regulations was correct.

WHAT IS A DIFFUSER?

It is the rear part of the floor of the car between the rear wheels and under the rear wing

It is crucial to the aerodynamics, and small changes can have a big impact on downforce – and therefore grip and speed

"Therefore we had every confidence that the design of our car would be confirmed as legal, firstly by race stewards in Australia and Malaysia and subsequently by the Court of Appeal."

The judges in Paris heard evidence from both sides, with Ferrari’s legal representative, Nigel Tozzi QC, describing Brawn GP team boss Ross Brawn as "a person of supreme arrogance". Brawn defended himself robustly and insisted his team’s diffuser was simply "an innovative approach of an existing idea".

And Brawn’s criticism of Ferrari consultant Rory Bryne and Red Bull technical guru Adrian Newey saw sparks fly in the courtroom, with the Englishman refusing to retract his statements. FIA technical director Charlie Whiting was also grilled, with accusations his organisation are "getting it wrong, and not understanding the point".

via BBC Motorsport