Webber sets pace before electrical problem

Mark Webber set Friday's fastest practice time, but the Australian also sat out the end of the afternoon session while Red Bull repaired an electrical problem.

But in the sister RB6, 2009 winner Sebastian Vettel had been the quickest runner in the morning, demonstrating that the Austrian-owned team is still the favourite for British Grand Prix victory.

McLaren debuted its Red Bull-like blown exhaust layout on Friday, but Lewis Hamilton - the fastest of the two MP5-25s - was 1.5 seconds off the pace.

His teammate Jenson Button, nearly two seconds too slow in the afternoon, said: "We know it (the new package) will take a little bit getting used to and I am sure there is setup work needed, so we are going to have a busy couple of days getting it right."

Closest to Webber's ultimate pace was Fernando Alonso, but the Ferrari was four tenths slower in the afternoon session.

"I am quite optimistic for the weekend, but we know the characteristics of the track are maybe not the same as Canada or Valencia, so we will see," said the Spaniard.

"I think Red Bull are clearly the favourites at the moment," added Alonso.