McLaren appears to have no choice but to remain with Honda in 2018 after talks between Red Bull and Honda over a possible Toro Rosso supply deal ended in failure.

Though a successful deal was no guarantee, with Honda looking for a customer team after a contract with Sauber was cancelled a few weeks ago, it was thought if the Italian team did a tie-up with the Japanese manufacturer with 2018 or 2019 that could open the door for a potential switch to Renault for McLaren.

However, with the Toro Rosso negotiations failing and with Mercedes and Ferrari unwilling to supply the Woking-based outfit due to fears of being beaten and other factors, it leaves them seemingly no alternative than to try and make their ongoing project with Honda, which began in 2015, work.

"Renault, which will continue to supply three teams including Toro Rosso, has a convenient riposte to any pressure put upon it to supply McLaren: namely that supplying a fourth team could impact upon development and reliability," Sky Sports contributor Mark Hughes wrote for Motorsport Magazine.

The only way McLaren won't be powered by Honda engines in 2018 now is if bosses at the Japanese carmaker decide to pull out of F1. Under that scenario one of the three other suppliers would have to begrudgingly agree to sell their units under an agreement made two years ago when Red Bull faced the possibility of not having an engine.

As it is, Honda still remains committed for now, with the head of their F1 operation Yusuke Hasegawa revealing potentially three further upgrades were planned this season as they look to be overcoming the major reliability problems from the first half of this season.