Red Bull forced to stop running on Jerez Formula 1 test day two

The reigning champion team had only managed to complete three laps on the opening day on Tuesday because of delays caused by a part being fitted incorrectly ahead of its first run.

Its hopes of getting valuable mileage under its belt on Wednesday were then dealt a blow when Vettel was confined to the pits by what is understood to be a Renault energy store issue early in the afternoon.

The team elected to abandon its running for the day so Renault could be given more time to look into the problem and sort a solution for Thursday.

Vettel has cancelled his media commitments for Wednesday evening and will fly home.

His new team-mate Daniel Ricciardo will take over for day three as scheduled.

Vettel's issue comes amid a difficult start to the week for Renault, whose mileage has lagged behind its rival engine manufacturers.

With just over than two hours to run on Wednesday, Mercedes had completed 115 laps with its teams, Ferrari has managed 56 while Renault had done just 11.

Renault's engine chief Rob White admitted after the opening day of testing, where various teams were beset by troubles, that the situation needed to improve dramatically.

"I honestly expected there to be more laps on the board right now, but without real up close knowledge of what has been going on in the garage I don't know what has been happening," he said.

"It is kind of a no brainer, but the pace has to ramp up substantially over the coming days and week."