Jacques Villeneuve could retire (unlikely), or return to IndyCar racing in North America if he loses the World Drivers' Championship as a result of the impending FIA appeal hearing which is expected to strip him of his fifth place in Sunday's Japanese Grand Prix.

The 26-year-old Canadian was originally disqualified from the race after passing a yellow flag at undiminished speed in free practice at Suzuka.

He is one point ahead of Michael Schumacher, but if the FIA stripped him of the two points he earned for fifth in Japan, he would go into the final race in Spain on October 26th trailing the Ferrari driver by a point.

Now Williams are worried that, in that situation, Schumacher could deliver Ferrari's first world drivers' title in 18 years by repeating what he did in the 1994 Australian Grand Prix when he collided with Damon Hill.

"The man who goes into the last race in the lead is in a position where he can, as we have seen a number of times in previous years, be very aggressive with the person behind him," said Williams technical director Patrick Head.

"I think that is what happened with Damon in 1994 - I think that was a deliberate removal of a competitor. So, the man who goes there with fewer points is in a position where he has to be very careful if he is challenging for the lead."

But Schumacher yesterday insisted he will not indulge in dirty tricks to beat Villeneuve to the world title. He played down speculation there would be a repeat of his infamous collision in Australia.

Equally, Schumacher warned he would not be cowed into giving Villeneuve space if the two rivals end up battling with one another during the decider in Spain.

"I will be aggressive if necessary," he said. "It's the last race of the season and whoever finishes in front is world champion."

Schumacher has 78 points and Villeneuve 79, but the Williams team, who clinched their record ninth constructors' title with Frentzen's podium finish, expect to lose Sunday's fifth place and collect a massive fine if they lose their appeal.

If Villeneuve should lose the championship, sources close to the Williams team hint that he could quit racing altogether, even though he has a lucrative, £10 million contract in place to drive for Williams to the end of 1998.

Villeneuve, a free-wheeling and fiercely independent competitor, has frequently said that he would quit the sport if he stopped enjoying it. "I did not enjoy this weekend," he said frankly at Suzuka.

But Head, denied firmly that Villeneuve had signalled any intention of stopping. "He has a contract in place with us next year and nobody has even suggested he might stop," he said. "I have never heard anything to that effect."

Head believes that Villeneuve is well capable of beating Schumach er's Ferrari in a straight fight for the championship.

Rather than retiring, it is more likely that Villeneuve will announce at Jerez that he is joining the planned Reynard F1 super team who will make their debut in 1999.

The official launch of this new team, masterminded by Villeneuve's long-time manager and mentor, Craig Pollock, and reputedly backed with a £150 million, five-year budget from British & American Tobacco, is expected at the Spanish event. Williams have already inquired about the possibility of securing the services of the young Italian driver, Jarno Trulli.

Trulli, who led the recent Austrian Grand Prix for almost half its distance in the Prost Mugen Honda, is negotiating to stay with the French team at least for 1998.