Cyril Abiteboul has said that he is imposing no "ultimatum" on struggling Renault driver Jolyon Palmer.

Rumours are rife that the extent of Palmer's struggles to keep up with Nico Hulkenberg means the team are considering dumping him mid-season.

Renault boss Abiteboul admits that Palmer needs to improve.

"We cannot afford this situation," he told Auto Motor und Sport.

"Jolyon must be able to make a contribution, but I have no doubt that he can.

"So I place no ultimatum on him. He and we know he can take this car into the points, and that's what he needs to do."

Abiteboul says that Palmer's issue at the moment is himself.

"It is clearly a matter of self-confidence," he said. "He has not lost his qualities as a driver that we saw last year and in GP2.

"There have been reliability problems on his car and a teammate who is extremely fast, and he fell into a downward spiral. Now I want to protect him and his family."

When asked if he can rule out dumping Palmer mid-season, Abiteboul answered: "At this time I rule it out.

"It is a hard time for him and for us, but we go through it together."

Palmer has yet to register any points this year, in comparison to Hulkenberg's haul of 18.