Mercedes team chief Toto Wolff believes Formula One can survive if Red Bull and their sister team Toro Rosso walk out, but at a cost.
On the eve of opening practice for this weekend's Russian Grand Prix, the two teams remain without engine deals for 2016.
Red Bull owner Dietrich Mateschitz has made it clear that if they cannot find a competitive top-quality supplier he would be prepared to walk away.
Both Mercedes and Ferrari are reluctant to help Red Bull out – Mercedes having rejected the idea and Ferrari saying they do not want to give them an up-to-date power unit.
"I would say that, definitely, losing Red Bull and Toro Rosso like that would not be good for F1," said Wolff.
"It would be a big loss. So I hope it does not happen. Red Bull is a very hip brand and it is important for F1.
"I hope they can find an engine supplier. I know that negotiations are ongoing, but not with us. Let’s see how it pans out…"
Many close observers of the latest threat to the sport believe that a Red Bull departure would have a devastating effect on its image and brand.
"I think that in the current circumstances it is important to keep all teams, but we have seen teams coming and going," Wolff added.
"I am not saying Red Bull is any is different to the others. It is a great brand, but a few years ago, in just 18 months, we saw that Toyota, Honda and BMW all left and F1 survived.
"Our emphasis at the moment must be on trying to keep them in the sport. If we cannot, because it is taken out of our hands, I think F1 can survive but it is not ideal."

Source: AFP