May 23 (GMM) McLaren looks set to be the only Honda-powered team in 2015.
The great British team is already signed up to be Japanese carmaker's 'works' partner, but it had been reported that Lotus, Sauber and Williams had enquired about becoming customers of Honda's turbo V6 engine.
Indeed, it was believed that - under FIA rules - Honda was actually obliged to make available its engines to one or more customer teams when it returns to F1.
"To my knowledge there is nothing in the regulations forcing an engine supplier to supply several teams," he reportedly told The Racer's Edge.
"So we look forward to an exclusive collaboration with Honda," the McLaren boss added.
Whitmarsh also seemed to play down reports linking Japanese driver Kamui Kobayashi with a possible return to F1 in McLaren's new Honda era.
"If we did that (signed a Japanese driver), it would be a driver that we have helped to develop," he said.