FIA President Jean Todt believes the four manufacturers currently competing in Formula 1 must be respected in the talks over changes to the engines for 2021 which it is hoped will attract new suppliers to the sport.

Three of the four manufacturers issued strong concerns about the proposals put forward back in October by F1 bosses and the FIA with Ferrari and Mercedes both threatening to leave if they did not agree with the direction taken.

Managing Director of Motorsport Ross Brawn has stood by the need for simpler, cheaper and noisier engines which are already attracting interest from the likes of Porsche, Aston Martin, Cosworth and more but Todt stressed the need to support those already present.

"What I feel would be unfair would be to undervalue the existing engine suppliers involved and listen to those who may think they will come," he said. "For me, it is important in light of the existing situation to see what will be the best evolution of the engine for the future, but by respecting the investments of those who have made the investments so far."

Indeed, the Frenchman, who was a staunch backer of the move to hybrid engines in 2014, would agree that there are problems with the current power units which need addressing but made it clear any changes should be done in line with the direction currently being taken.

"Clearly if you ask me what I feel about the engine - it has been one interesting exercise," he said. "I think it is too complicated, too expensive but it is probably a very good first step to go to the next generation of engine, which will be one evolution from what we have now.

"I am against starting on a completely new development of engine but I think we should take what we have understood with this engine and allow the actual manufacturers who have been investing heavily to be able to enjoy what they have been investing for the next generation of engine, and also encourage newcomers to come."