Ahead of its third season since its return as a constructor, Renault has admitted that it is against the idea of a major overhaul to the engine rules in 2021.

Currently, the aim is to retain the current 1.6 litre hybrid formula, albeit with a few tweaks, most notable being the inclusion of more standard parts, a higher rev limit and the dropping of the (costly) MGU-H.

Talk of more standard part was enough for Ferrari to raise the roof, the Italian team warning that it will leave F1 for a breakaway series.

While Mercedes has taken a calmer approach, the German manufacturer has warned that - at a time the sport is supposedly focussing on budgets - it doesn't want to be placed in a position where it is effectively running two engine programmes simultaneously.

As present, F1 and the FIA have only put forward a proposal for the 2021 engine formula, but now Renault has warned that it too would be unhappy with too radical an overhaul to the rules.

"We would like to avoid almost starting from scratch again," Cyril Abiteboul told Motorsport.com. "If I look at the investment that has been made in the engine, if I look at the time that it is taking to get to a situation where it is not a level playing field, but that the engine is not a handicap anymore for chassis people, because that is what you want, a disparity where a team is not prevented from winning races or doing a decent job by its engine partner, frankly starting from scratch again is quite frightening."

A major driving force behind the introduction of the hybrid formula, Renault, which dominated the final years of the previous formula, has never quite come to grips with the new formula since its introduction in 2014. While it has won races, it has never been in a position to mount a serious challenge to Mercedes as Ferrari did in the first half of 2017.

While he is hopeful that between them the various parties will be able to come to an amicable rule package, Abiteboul warned that time is of the essence in reaching an agreement.

"I feel everyone is willing to have constructive dialogue and get very quickly to a solution," he said. "Having said that, we are not going to commit to a new engine without knowing what F1 will look like in 2021."