BAR launched their new Formula One car on Sunday with team boss David Richards insisting lead driver Jenson Button is not for sale.
BAR are optimistic that their new car will be competitive
The Englishman has been linked with a move back to Williams in place of Colombian Juan Pablo Montoya, who is moving to McLaren in 2005.
But Richards insisted there is no reason for the 23-year-old to leave.
"Jenson is not for sale. There's not even a reason to discuss the situation with other teams," Richards said.
BAR launched their new car in Barcelona, and have already claimed they will be able to challenge the top teams in 2004.
Last season Button finished ninth in the drivers' standings and Richards, who has first option on his services when his contract expires at the end of the season, aims to build the team around the driver.
"We're working very well together, we're improving all the time and I'm sure Jenson sees his future with this team and being successful with this team," he added.
"Why would Jenson want to go to another team if we're making such progress?
"We're getting quicker and quicker, we have a contract with him, so why would Jenson want to move out of here?"
McLaren chief Ron Dennis has been particularly complimentary of Button in recent weeks.
"Jenson has got what it takes to be a world champion," said Dennis.
"He did lack a bit of discipline now and again, and could be a bit of a
showman, but he is a pretty competent driver and has grown up."