Williams will Not Let Button Go

Button needed to score 75 percent of the World Championship leader's points after next month's Turkey Grand Prix to escape a contractual tie that Williams have over him for 2006.

After a disastrous start to his campaign, however, it is impossible for him to achieve that target - and the terms of the contract means that he must now go to Williams and the team must take him.

And although Button is believed to prefer to stay at BAR next year and is understood to have made attempts to get out of his Williams contract, team boss Frank Williams said they are not going to let him go.

Speaking to ITV, Williams said: "We do have an existing contract for Jenson for 2006. We fully expect him to arrive at Williams at the due period of time."

Williams said that the continued uncertainties over their future engine supply had no implication on the contractual situation, and when asked whether there was anything that would convince the team to release Button, Williams was insistent.

"There is nothing that will change that," he said.

BAR are keen to retain Button for next year and team boss Nick Fry has said ideally he would like the Briton to see out his F1 career with the team.