Like most messy divorces, even after Red Bull and Renault had gone their separate ways, the mudslinging continued, neither party missing an opportunity to hit out at the other.

While they were winning titles it was the dream marriage, but with Renault caught out so badly by the very hybrid formula which it had pushed for, things soon turned ugly.

However, following Honda's announcement that it is to leave F1 at the end of next season, the Red Bull teams options are limited. Both Mercedes and Ferrari have firmly turned down their previous requests and now, barring the Austrian company funding the development of its own engines, possibly by buying the Honda operation, the only apparent alternative is Renault.

Appendix 9 of the sporting regulations obliges the manufacturer with the least number of customer teams to supply any competitor that has no alternative supplier.

With McLaren in the final year of its partnership with Renault before switching to Mercedes, this leaves the French manufacturer with no customer teams, therefore, as Cyril Abiteboul admits, his company would be obliged to supply its former partner(s).

"We know the regulations and we would comply with the regulations," he told Reuters.

Under the regulations, engine manufacturers do not have to advise the FIA who they are supplying from 2022 until next May.

"I guess that it is only at this point in time that will be discussed if Red Bull fail to find a solution, which I really hope will not be the situation," admitted Abiteboul.

"When you participate in a sport you need to accept the obligations that are associated. As far as we are concerned, it's part of the sporting regulations and we would comply to this obligation."

In a separate interview he told Motorsport.com that thus far there has been no contact from Red Bull.

"I can confirm there was absolutely no conversation to this point," he said. "Being in the sport we are well aware of the regulation, and we have every intent to comply with the regulation and with our obligations.

"Obviously it's a bit more detailed," he continued, "we need to be requested, and we have not been requested yet, and secondly there are very specific circumstances, including timing, for this to happen. And we are still quite far from that window, which is not before the spring of next year.

"We know that in F1 lots of things can happen in a very limited amount of time, and spring 2021 is still very far. All sorts of things can happen. As I say we will comply with any obligation which may arise from this circumstance."

Asked if re-partnering would be awkward, all things considered, he admitted: "I think so... but we need obviously to look at the sport. And I think we are still very far away from having to possibly cross that bridge.

"I can't imagine that Red Bull would not have some plan in the background," he added. "Clearly they must have been aware of this, and Helmut and Christian are full of moves and solutions. I don't expect that we will be their Plan A!"

Asked if he was surprised by Honda's announcement, he said: "I knew that they had to confirm their position after 2021, and now that was probably the time to do that - and maybe the lack of confirmation was already an indication, because when I see how advanced we are already into the 2022 engine design I guess it's de facto some form of orientation."