With just over a week to go before the start of the 2005 season, Jenson Button must be wondering what the future holds for him.

While the BAR 007 has hardly been a revelation during pre-season testing, neither has the WilliamsF1 FW27. At this stage there seems to be little to choose between the two.

However, looking ahead to 2006, Button knows that should BAR be unable to meet the strict terms of the performance clause in his contract, he'll be taking the place of either Nick Heidfeld or even Mark Webber at Grove next season.

His contract states that by 31st August, Button must have at least 75% of the world championship leader's points, otherwise he's free to leave for WilliamsF1 at the end of the season, and there's nothing that BAR can do about it, Contract Recognition Board or no Contract Recognition Board.

However, talking to journalists at a pre-season press lunch yesterday, Frank Williams revealed that the situation is even more complicated than it appears. Apparently, if the performance clause is not met, WilliamsF1 must guarantee the Englishman a seat.

Therefore, in the unlikely scenario of either Webber or Heidfeld winning the championship, one of them would still have to give way to the Englishman, who would be entitled to demand a drive.