By Andrew Benson
The bosses of the BAR-Honda team face an anxious wait over whether they will be expelled from the F1 championship over alleged cheating at the San Marino Grand Prix.
BAR face an anxious wait ahead of the FIA appeal verdict
BAR say they are confident of winning their appeal, but on the face of it the team could be in trouble.
Jenson Button's car was 5.4kg under the minimum 600kg weight limit, and the rules say that cars have to comply at all times.
While it is not common practice for scrutineers to drain out all the fuel before weighing a car - as they did to Button's after the race - there is nothing to say they cannot. And the car must still not be underweight.
BAR's big problem is that very few teams ever score an outright win when they go into battle with the FIA, the sport's governing body, over a rules issue.
Despite being cleared by officials after the race, Button could well lose his points for third place in Imola.
But depending on how seriously the nominally independent FIA court of appeal views the team's actions, all options are open to it - including throwing the team out of Formula One.
Button is likely to lose his podium - but will the punishment be worse?
And it is at that point that the waters get murky - as they always seem to do in F1.
It could be that BAR made a simple error and miscalculated the weight of the car - although 5kg is a reasonably substantial amount, it is not inconceivable that could have happened.
In that case, disqualification from the race would be the likely punishment - unless the court, like the Imola stewards, accepts BAR's explanation.
But some F1 insiders believe BAR had a concealed secondary fuel tank that could retain fuel pumped into the car at the final pit stop.
Such a device would allow the car to run underweight for most of the race, with the extra fuel used as ballast to ensure it complied when checked at the end.
If this is true, it is deliberate cheating and BAR face very serious sanction indeed.
But unnamed BAR insiders quoted in the Guardian newspaper say that the tank is a collector system for the Honda engine's high-pressure fuel pump, which is not concealed and which is a system common to a number of other F1 cars.
Illegal ballast has cropped up several times in the sport's history because weight is such an important issue in F1.
FIA president Max Mosley is in dispute with many F1 teams
The lighter a car the faster it is - hence the need for a minimum weight limit, to ensure teams do not build dangerously frail cars.
What makes this situation even more complicated is that it has occurred against the background of the bitterest political infighting in F1 for many years.
Most of the teams are in dispute with commercial boss Bernie Ecclestone and FIA president Max Mosley over the future direction of the sport, with Ferrari the notable exception.
Five of the sport's car manufacturers and seven of the 10 teams are threatening to set up a rival championship in 2008 if they do not get a bigger share of F1's income and more say in its administration.
And it is no secret that Honda - which owns 45% of BAR - and its Japanese arch-rivals Toyota have angered Mosley and Ecclestone by siding with the breakaway faction.
It is a sad reflection of the current state of the sport that the first reaction of many people in the F1 paddock when hearing of BAR's problem was that the team were being picked on by the FIA.
Among BAR's concerns will be that, rightly or wrongly, few people retain much faith in the ability - or the desire - of the governing body to remain objective.
Imola was BAR's best race of a so-far disappointing season
There is a strong sense in F1 that the FIA has an unhealthily close relationship with Ferrari - a feeling that has grown up over many years of controversial decisions apparently going the world champions' way.
Not only that, but so difficult to predict has been the FIA's behaviour in resolving technical disputes in recent years, that few would be willing to guess which way it will jump on any single issue.
The most striking of these incidents was when the FIA controversially overruled the disqualification of both Ferraris at the 1999 Malaysian Grand Prix - a decision that kept the world championship open until the final race.
But there have been many others, all of which are well known to BAR's top personnel.
With that in mind, it would be no surprise if the bosses of BAR and Honda have had a few sleepless nights waiting for the FIA to reveal its verdict.