It was announced in Tokyo on Thursday that McLaren will be powered by 'works' turbo V6 engines provided by Honda from 2015.
But, before then, McLaren will run with customer Mercedes power next year, as the sport switches to the all-new and radical engine regulations.
The situation has raised some red flags: will the development of Honda's new V6 benefit from the insight gained from the ongoing McLaren-Mercedes pairing?
Is Mercedes' intellectual property in danger?
"We have discussed that at length with Mercedes," said McLaren managing director Jonathan Neale, "and we have made sure Mercedes has all the comfort it needs.
"It is not in Honda's interests either," he insisted. "Honda is very honourable as an organisation, as is Mercedes.
"McLaren will operate in a scrupulous way between both of those two organisations."
Neale said it is in both Mercedes and McLaren's interests to ensure the 2014 collaboration - prior to the shift to Honda - is successful.
"We need each other to be successful, so we have a confidence in our partnership," he added.
"We recognise there is mutual dependency. Although we are competitive on circuit, behind the scenes there is the highest of regard between the two organisations."