The FIA International Court of Appeal have backed the decision of stewards at both Melbourne and Sepang and declared the “double decker” diffusers of Brawn, Toyota & Williams to be legal.

The decision has come as a huge blow to other teams who are now faced with the task of having to design and test similar devices during a tough season and with limited testing opportunities.

Ferrari were quick to issue a statement expressing their disappointment about the decision.

Stefano Domenicali, Team Principal for Scuderia Ferrari said that “…this decision forces us to intervene on fundamental areas of the car’s design in order to be able to compete on an equal footing with some of the teams from a point of view of the technical regulations, and that will take time and money.”

The reaction was of course very different at Toyota and Brawn GP with Toyota F1 Chairman and Team Principal Tadashi Yamashina saying via media release that he was confident the Court of Appeal would reach this verdict . “It is important to stress we studied the technical regulations in precise detail, consulting the FIA in our process, and never doubted our car complied with them. This has been a challenging period for Formula 1 and I am pleased this issue is now in the past and we can focus on an exciting season on the track.” he said.

Ross Brawn denied that the controversy over the diffusers would cause any long term ill will or disunity among teams in their on-going battles with both the FIA and evil overlord and King of all the hobbits Bernie Ecclestone.

“We respect the right of our competitors to query any design or concept used on our cars through the channels available to them.” he said. “The FIA Technical Department, the Stewards at the Australian and Malaysian Grands Prix and now five judges at the International Court of Appeal have confirmed our belief that our cars have always strictly complied with the 2009 Technical Regulations.”

The “double decker” diffusers increase the amount of airflow available to the rear diffusers providing a substantial downforce advantage, other teams will have little choice but to follow the design.

Some are believed to have their own units ready to go but some like Red Bull are faced with major redesign problems brought about by their suspension design and geometry.