The 2009 Formula One World Championship may be defined tomorrow in the FIA International Court of Appeal. All the teams except Force India and Toro Rosso will be in Paris to debate the legality of several car designs that appeared at Albert Park and Sepang. The top three contenders are those under scrutiny and, although it is highly unlikely, there is a possibility that Brawn, Williams, and Toyota will be excluded from the first two races of the season.

It would be a great shame if that were to happen, but it is a shame the argument over ‘illegal’ diffusers has reached this point anyway.

The technical regulations underwent a major change this year in order to make overtaking easier for the drivers. Part of the new rules package included a greatly reduced diffuser, but some of the teams have worked a way around this restriction and that is what the others have brought to the FIA’s attention.

As air rushes beneath the car it is sucked into the diffuser and spat out the back. This is done through a series of channels that are cut into the floor, and as the air passes through them it is forced to expand, sucking the car to the ground.

Limiting the size of these channels reduces the amount of air that can pass through them, and therefore the amount of downforce they can generate. The rear diffuser on an F1 car contributes up to 40% of the chassis’ total downforce so its importance is not to be understated.

When the Toyota, Williams and Brawn cars were unveiled during winter testing it became clear their diffusers were sucking through more air than the new rules intended. They hadn’t gained this advantage illegally but had instead exploited a loophole in the regulations.

The ‘trick’ diffusers have been constructed within the appropriate size limitations but everything around them has been shaped to increase the downforce they can generate. Toyota started using the bottom of their rear crash structure to create extra volume inside the central diffuser channel, whilst Brawn and Williams built theirs so air passes around the diffuser as well as just inside it.

Their designs are legal according to the regulation wording, although they aren’t within the spirit of the new rules.

A number of teams suggested in preseason testing the cars were illegal and announced their intention to raise the matter further. However, the FIA ignored their initial objections. Max Mosley said “the view on our technical people is that it is okay, we will wait and see if someone challenges it”.

The FIA would have been wiser to have issued a technical clarification there and then because it would have avoided the mess that has since unfolded.

At the Australian Grand Prix Ferrari, Renault, and Red Bull (a Renault customer) protested the legality of the Brawn, Williams and Toyota designs. Stewards at the race meeting threw out their protest but this decision was instantly subject to appeal and that is the case being heard tomorrow.

In Sepang BMW also launched a formal protest which ensures the second round of the championship can now be discussed during the same hearing.

Essentially, four teams are challenging the results of another three.

It is likely to be a heated atmosphere in the Court of Appeal because the verdict will have a massive bearing on the World Championship. Brawn, Williams and Toyota have been the quickest teams so far in 2009 and a sudden change to the regulations might knock them over.

Flavio Briatore has been unsurprisingly outspoken about the upcoming case. The Renault boss said his team felt hard done by and was so committed to having the trick diffusers declared illegal that “to make us give up they have to kill us. We’re going all the way.”

That is pretty full on, and is an indication of how much this means to the teams involved.

Briatore also launched a scathing personal attack on Ross Brawn, labelling him a “bandit” for supposedly abusing his role in the FOTA Technical Commission. Flavio believes that Ross should have used his position in FOTA to warn other teams about the impending diffuser situation instead of hiding it for Brawn GP’s benefit.

Briatore said “Brawn should have been fair. Three months ago he should have come to us to tell us there are two interpretations over the diffusers. When I go to the FIA or to Ecclestone, I go in the name of the FOTA, not Renault. I don’t like the fact that a FOTA representative didn’t relate things transparently.”

However, Briatore is blatantly wrong to suggest that Ross Brawn did nothing to avert the present debacle.

The teams had a very big hand in writing the new rules and did so in cooperation with each other. The regulations were formulated by the Technical Working Group and the Overtaking Working Group before being published by the FIA.

In March 2008 during a meeting of Technical Directors, Ross Brawn noted there was potential to gain more downforce than intended under the new rules. He tabled some proposed changes to the regulations that would, amongst other things, have made trick diffusers illegal. The other technical directors were not interested in his suggestions and some felt they were too restrictive. According to Patrick Head, it was Renault’s Pat Symonds that was most against Brawn’s proposal which is somewhat ironic given Briatore’s comments.

It was a mistake in that meeting to ignore Ross Brawn’s advice because the rules could have been cleared up twelve months ago instead of in court after two races have finished.

No-one is sure exactly how the appeal hearing will progress tomorrow but there are three possible outcomes.

The first is that trick diffusers are given the okay and that teams without them have freedom to introduce one.

The second is that an amendment is made to the regulations so Brawn, Williams, and Toyota are forced to change their cars before the Chinese Grand Prix. Everyone will then have the same basic diffuser as originally intended twelve months ago.

The third, and most extreme outcome, is that Brawn, Williams, and Toyota are declared to have breached the technical regulations and are excluded from the Australian and Malaysian Grands Prix.

It is highly unlikely the results of past races will be changed but it is still a remote possibility.

The championship table will look very different if the fastest three teams are removed.

Fernando Alonso would be given the Australian Grand Prix victory, and both Toro Rosso drivers would score big points for finishing right behind him. The two Force India cars would be elevated into fourth and fifth, whilst Vettel and Kubica would receive points despite their late race collision.

The Malaysian results would also take on a radical new shape. Heidfeld would be given the win at Sepang with Webber and Hamilton making up the top three. Bourdais and Alonso would also score points along with both Ferrari drivers.

Fernando Alonso would take the championship lead and his closest rival for the top spot would be Sebastian Bourdais just 1.5 points behind.