Timo Glock (right) has laid down a marker for the rest of the field at a very overcast Silverstone circuit by taking the top spot in free practice, just ahead of Mike Conway and Kazuki Nakajima.

The German driver was clearly keen to make amends for his disappointment last weekend in France, and was comfortably fastest with a time of 1:29.371 - despite finishing just 0.059 ahead of his nearest rival he looked faster on a number of other laps until he came across traffic.

The session started poorly for new driver Filipe Albuquerque, who had a problem with his downshifts on his out lap and spun at Chapel, and then was unable to get down to first in time and stalled, prematurely ending the session for him.

In the opening minutes the lead changed between Karun Chandhok, Conway and then Glock, who kept the top spot from six minutes into the session until the end by improving his times throughout to remain just ahead of the Briton.

Vitaly Petrov was stuck in the pits for the first half of the session as his team worked on his engine - when he finally got on track his exuberance took its toll with a small spin, but the Russian soon put it behind him as he tried to get back in touch with his more fancied teammate.

Bruno Senna, who had been vocal in hoping for rain this weekend at what has become his home circuit, pushed hard throughout - he lost his rear out of Copse towards the end as he was looking for more improvement, and he had to make do with the fourth best time, fractionally behind a rapid Nakajima and ahead of countryman Lucas di Grassi, with Adam Carroll rounding out the top six positions.

With the rain arriving just as the cars were rolled back into the paddock qualifying promises to be as exciting as ever, with the top nine drivers separated by just one second in the dry session.