Red Bull principal Christian Horner has admitted that Red Bull may have to quit Formula 1, if engine partner Renault leaves the sport.

The French supplier has come under fire for the performance of its engines this year, which has prompted motorsport boss Cyril Abiteboul to reveal that Renault was considering its options regarding grand prix racing.

However, Horner has suggested that the four-time constructors' championship may be with left no choice but to exit Formula 1 if Renault do leave.

Horner is quoted by The Mirror as saying: "Should Renault withdraw, Mercedes wouldn't supply Red Bull with an engine and it's unlikely we would be in a position to take a Ferrari engine.

"So we could actually find ourselves forced out of the sport."

Red Bull finished second in the constructors' championship last season, 306 points behind Mercedes.