Renault took over Lotus at the end of 2015 amid a breakdown in the relationship with Red Bull, but while returning as a constructor it also extended its supply deal which allows Red Bull to badge the power units as Tag Heuer.

Red Bull won the Spanish Grand Prix and Daniel Ricciardo looked set to win from pole position in Monaco but for a pit stop error, with a power unit upgrade helping close the gap to Mercedes. Renault ambassador Prost says the recent progress could see Red Bull challenge the defending champions for the rest of the year.

“They could be a challenger, maybe a big challenger, for Mercedes, definitely,” Prost said when asked about Red Bull’s chances this season. “But I don’t think Renault can do much more for the engine, but for sure there will be some more improvement.

“But [Renault] are very happy … unless [the constructor team] are going to become competitive – which is not today – they are very happy to see the engine winning and Red Bull to be a contender. I’m not jealous at all, for sure!”

And Prost says Red Bull’s success can act as motivation for Renault’s constructor team as well as validation of the power unit.

“I think it’s a very positive thing, in this situation. It’s a constructor team, so you have an engine and chassis together now, so it can be a positive fight or competition. At least you know the engine is working well and it can be very good for the people making the engine, very good for the image, very good for Red Bull.

“It means you can concentrate, and it gives a nice motivation, a nice vision for the future. It is almost like ‘this part is working, so we can do even better’.”