Jenson Button has refused to commit his long-term future to McLaren.
Button, who joined McLaren last year, signed a new multi-year contract with the team yesterday but has denied that the relationship will continue throughout his career.
"Not necessarily. Probably two years ago I would have said definitely, and even last year I probably would have said definitely", the PA quotes the 31-year-old as saying.
"But time flies and when I decide I want to retire from Formula One I think will end up going back and back. Hopefully it will be my decision, so [the new contract] might be [my last] or it might not be. I don't know."
Button, who had been linked to a move to Ferrari or Red Bull, is currently second to Sebastian Vettel in the world championship standings.
