Eric Boullier says McLaren remains steadfast in its view that its relationship with Honda should remain an exclusive one amidst speculation the Japanese firm could supply Red Bull in 2016.
With Red Bull Racing still seeking an engine deal for 2016 having parted ways with Renault and been rejected by rivals Mercedes and Ferrari, Honda has subsequently emerged as a candidate.
Originally dismissed as an unlikely option for Red Bull given the power unit engine's struggle for competitiveness in 2015, it is McLaren's insistence to remain Honda's exclusive partner that could prove the more significant hurdle to overcome.
Though it isn't clear whether McLaren's influence extends as far as a much rumoured veto that it can exercise to prevent other Honda tie-ups, Boullier maintains its collaboration was sought on the premise that other customer teams wouldn't be involved.
“We wanted to work with Honda as an official partnership because having an official partner is the only way we believe to be world champions. As a customer of an engine manufacturer you can't be world champion. This is a privilege we found and we don't want to share.”
His words come after Bernie Ecclestone appeared to confirm that a deal was being blocked by McLaren CEO Ron Dennis, even though an FOM/FIA agreement that stipulated Honda could be allowed to supply other teams from 2016 can be enforced. It was statement Boullier was unwilling to discuss, however.
McLaren-Honda enjoyed one of its strongest races of the season in the United States, with Jenson Button finishing sixth, for his best finish of 2015.