Renault has told Red Bull it has until May to decide if it wants to continue using the French manufacturer's engines after 2018, or switch to Honda.
Red Bull is coming to the end of its deal to use Renault engines – which are rebadged Tag Heuer – with 2018 the final year of the current contract, but with sister team Toro Rosso switching to Honda, there is the possibility of Red Bull doing the same.
Renault boss Cyril Abiteboul has therefore insisted a decision must be made by May 15 – the date specified in the regulations by the FIA.
"We are not going to hang around forever," said Abiteboul. "I know what Christian [Horner] is referring to when he says that he has options.
"Like him I know and read contracts and obligations that we have to help the sport, not to help Red Bull Racing, but there is one thing that is clear, that’s planning. There will be a deadline for Red Bull Racing to define what they want for the future."
When asked what that deadline would be, Abiteboul replied: "It’s available, it’s in the sporting regulations. I believe that it’s by the end of May. As far as I’m concerned that will be our deadline."
Abiteboul also discussed the future of Carlos Sainz, who joined the team on loan from Red Bull as part of last year's engine swap, and whether Red Bull could call Sainz back early, leaving Renault with a driver predicament.
"No, he’s on a loan contract for the full season," insisted the Frenchman. "It’s not like we are under the risk of losing him at any point in the season.
"For the future, I guess it’s like any driver or anyone coming to the end of their contract, we’re in no worse situation than any team with a driver on a one-year contract. We will want to talk about next year and the only difference is we will have to talk about next year with him and Red Bull Racing."
