Brawn GP will not allow world champion Jenson Button to be involved in any team activities for McLaren before the end of the year.
Brawn chief executive Nick Fry said they would view any such activities "very dimly", while also hinting he felt Button, who sealed his move to McLaren earlier this week, had been disloyal.
"Jenson will not be doing anything at all for McLaren until the end of this calendar year," said Fry in The Guardian. "And if he does, we will be looking on it very dimly.
"He didn't have any obligations to us in 2010, but there are issues with regard to the [McLaren contract] signing process on which we are in discussion with him at the moment.
"There are other constraints on what Jenson can do between now and the end of the year which we will be rigorously enforcing."
The stance, which will apply to activities both on and off the track, is unusual among Formula One teams, who generally allow departing drivers to join up with their new team after the final race of the season.
Fry also suggested Button would have his work cut out at McLaren, as well as bemoaning a lack of loyalty.
He said: "Clearly loyalty would be nice but in this day and age you don't expect too much of that.
"I am always happy when any employee leaves our company if they are going to a better job, and they always go with our blessing if that is the case.
"In this situation we don't see the logic of the decision and I think Jenson is going to have to up his game if he is going to beat Lewis on home territory."