Renault F1 chief Jean-Michel Jalinier insists the struggling French supplier should not be written off in 2014.

Many believe Renault's early-season problems with the all-new turbo V6 'power unit' have made winning races and the title almost impossible for world champions Red Bull.

But a bullish Jalinier hit back even at claims Renault is concerned it has already had to 'freeze' the specification of its engine for 2014.

"I am convinced that we have designed a good package," he is quoted by Italy's Omnicorse.

"We have to work on the software but that is outside the freezing. On the engine we worked until the last second to be sure we reached the right level of power and torque, and in this aspect we believe we are right."

Jalinier suggested some of Red Bull's problems have been exacerbated by the design of Adrian Newey's RB10 car.

"Red Bull have always made very competitive cars and we worked well together," he said.

"Maybe theirs is a bit more extreme at the level of their project, but we are working closely together to make it competitive," Jalinier added.

He denied rumours suggesting Red Bull and Renault could be set to split, with Lotus to take over as the 'premier' Renault team.

"At the moment," Jalinier insisted, "our team of reference is Red Bull and we have three other customers.

"Among them is Lotus, who have certainly proved to be a very competitive team, but our principal team remains Red Bull Racing.

"We still have a long-term agreement with the team in Milton Keynes ... there is no separation," Jalinier said.