Williams has ruled out using KERS for the remainder of the Barcelona test and may even choose not to use the system in Melbourne.

Despite having abandoned its controversial flywheel system in favour of a more conventional battery device, the Grove outfit, whose Williams Hybrid Power company has achieved success in other racing disciplines, continues to be plagued by problems. On Wednesday, Pastor Maldonado completed just 29 laps after a KERS caused the team to miss out on most of the day's running.

"We had a KERS fault first thing this morning," admitted Sam Michael, "we removed the system and were able to get out for some limited running late afternoon."

Although Rubens Barrichello completed 105 laps on Thursday, this morning, after just an hour of running the team revealed that it won't be using the device for the remainder of the Barcelona test.

Speaking to the Dutch website F1Today, Barrichello has admitted that the British team could opt not to use KERS in Australia. "We need to decide quickly what we are going to do," he said. "I hope we do not conclude that we have to race in Melbourne without KERS, but it is possible. It is an uncertain factor for us; one day it gives us no problems and the next day it gives us hundreds of problems."