With just four weeks of the F1 season remaining, Red Bull is still without a power unit for 2016 after deciding to part company from Renault, with Mercedes and Ferrari unwilling to supply.

Honda has been mentioned as a potential partner, despite its catalogue of issues this year on its return to F1, with the suggestion being they were happy to step into the breach.

Last week, however, F1 supremo Bernie Ecclestone revealed McLaren Group CEO Ron Dennis had blocked Honda from supplying after the Japanese manufacturer had “made a commitment to Ron he had a veto”.

With Dennis unwilling to come to Red Bull’s aid, the possibility of a supply appears dead in the water, only for Honda motorsport chief Yasuhisa Arai to claim on Friday the situation is “open”.

Boullier said: “As a partner, and I’m going to repeat myself, we have to agree on the strategies.

“This is not a question of Ron saying ‘no’ and Arai-san saying ‘yes’. There is no debate on this.

“Clearly there is an issue inside Red Bull, created by Red Bull and not by anybody else, and we are not a charity foundation, so we are not here to help.

“But we are not going into this kind of debate.

“Today there are discussions, but the position of McLaren-Honda has been made clear.”

As to Honda’s stance on the matter, Arai said: “Obviously we cannot discuss details at this moment.

“We have been approached by the team [Red Bull], but discussions are ongoing and nothing has been decided.

“I always say this season: we are always open, so we are in discussions that are ongoing – that’s it.”