Cyril Abiteboul says he has put together a "plan" to put Renault back on the right track by the French works team's home race in June.

"The start of the season was extremely unfortunate not just for us but for our fans and our sponsors," he told Auto Hebdo.

"At the height of this disappointment, there is a plan of action."

Abiteboul, the team boss, said he was horrified early this season to discover that the connecting rod or 'conrod' design in the engine was flawed.

He says that is now fixed, even though initially it had "disastrous consequences" for some time.

"We had to reduce the performance of the engine while we waited for the evolution. In Spain we were 50 per cent there and we are at 100pc for Monaco.

"Our goal this year was very clear: to finally be the best in this (engine) area," said the Frenchman.

"The good news is that we are in line with our performance goals. The bad news was that we had to take more risk.

"We put a whole bunch of engines on the test bench and instead of reliability, we validated performance items."

The reliability flaws aside, Abiteboul said the performance gain from 2018 to 2019 was "huge", and in the order of 50 kilowatts.

"In the race now, we are in the game. In qualifying, we still miss a little bit," he said.

As for the chassis, Abiteboul admits that Renault is still behind. "We have not progressed enough on the chassis side," he said.

"We are not efficient and not organised enough in our resource allocation decisions. Some big changes could not be completed in time but the good news is that they will arrive.

"There is a specific milestone in our calendar and it is the French grand prix. It is our commitment to be clearly higher on the grid with aerodynamic and mechanical developments as well as a new power unit."

And after that, Renault will press the foot even harder on the chassis development throttle, "similar to what we did on the engine," Abiteboul announced.

Overall, Abiteboul told Auto Motor und Sport that 2019 has been "unacceptable" so far, and he acknowledged that Renault is under pressure to show actual results to the carmaker's new executive management.

"But that is no different than under Carlos Ghosn," he said.

"If we deliver the results we imagine, the Formula 1 team will be worthwhile for Renault. But if we would have to invest as much as Mercedes, that is a different story."