WilliamsF1 boss, Frank Williams, has said that Jenson Button and his employers, BAR-Honda, can forget all about buying the English driver out of his contract with the Grove team for 2006.

Talking to reporters in Hungary on Friday morning, Williams made it clear that he is holding the driver to his word, with no ifs or buts.

"Williams has a fully-binding, straightforward contract," said Williams. There is no let-out. It is clear to understand. Jenson is emphatically, in capital letters, not for sale. We are a serious racing team and we need him.

"We require him to be here," added Williams. "Clearly many of our sponsorships are predicated upon his presence. We will defend our interests."

As Formula One prepares for the mid-summer break, it seems that for the second successive year, Button's future, and his problem in honouring contracts, will dominate the headlines.

"There needs to be a clearer understanding of the word commitment," said Williams. "Once you give your word, you should keep it. If I say to Jenson 'Oh, okay no problem, off you go' then over the next few years it will probably start a way of thinking for drivers that 'I've changed my mind, I won't bother now, I'm not coming'.

"You can't have this," he added. "You have got to have law and order everywhere, especially in Formula One."

As he tries to struggle free of the contract, Button is exploiting the fact that WilliamsF1 has lost its work engine supply from BMW, which he claims will destabilise the team, and consequently hinder his chances of World Championship success. Not so, says Williams.

"I look at the coming season and I say it's all change with the new engines, the order will almost certainly shuffle.

"We are a strong team with a strong past, a weak present and certainly in my own mind a strong commitment to the future," he added. "We are certainly as well resourced as any team in the paddock - we will be back and Jenson is part of our equipment to help us come back. We are looking forward to a British team with a British driver."