McLaren are reportedly considering parting company with Mercedes and replacing them with Honda.
German car giants Merc has supplied the Woking-based squad engines since the 1995 season and the two parties signed a new agreement in 2009 confirming that the "partnership may continue beyond 2015".
However, it now appears McLaren are looking to replace Mercedes as they are not happy to stump up the £8million that the manufacturer is asking for their engines from next season.
A source told The Sun that "there is no way McLaren will stay as a customer for Mercedes engines".
Auto Motor und Sport claims that Japanese car manufacturer Honda - who was McLaren's supplier when they dominated the sport in the late 80s early 90s - is the likely replacement.
The German publication reports that McLaren could team up with Honda when Formula 1 shifts to V6 turbo engines from the 2014 campaign.
Meanwhile, racecar-engineering.com reveals that the Japanese company is interested in a return to F1 as a supplier the season after next.
"The rumours are not unfounded but we have not decided anything, we are constantly evaluating the situation," a company source is quoted as saying.