Ahead of this afternoon's session, the air temperature is 26 degrees, while the track temperature is 45 degrees. It remains bright and sunny.

Nico Rosberg set the pace in this morning's session, but the McLarens were right up there with him. Interestingly, the German ran back to back laps one not using the F-duct, the other using it. His pace-setting time came on the lap he ran with the F-duct.

While McLaren waits until Silverstone before it introduces its blown rear wing, Ferrari, Mercedes and Renault used their versions to great affect earlier, while Williams and Red Bull ran their F-duct.

It's worth noting that four of the drivers in the GP2 practice session posted times quicker than the four slowest F1 cars.

Tyre options here are medium (prime) and super-soft (option) though we didn't see the option tyre this morning. Some drivers complained that their primes were going off after just one and a half laps.

The lights go green but nobody seems particularly keen to get to work, indeed, it is three minutes before Fernando Alonso gets the session underway, followed by Sutil and Petrov.

Alonso posts 1:40.850 having lost time in the final sector behind Kobayashi. Sutil, who didn't run this morning having handed his car to Paul di Resta, posts 42.920.

Massa is another driver keen to get to work, the Ferrari driver going second to his teammate with a 40.963. Petrov posts 41.943 to go third, ahead of Hulkenberg, Sutil and Kobayashi.

A 40.807 sees Massa go quickest but he is soon demoted by 40.625 from Hamilton. Elsewhere, Button is on track as Petrov and Kubica make it a 4-5 for Renault.

Button takes the top spot with a 40.586 only to be beaten by a 39.767 from Alonso. Massa and Kubica also improve.

As Schumacher begins his first flying lap of the afternoon, countryman Sutil goes second with a 40.020. Despite a massive slide, Schumacher goes seventh with a 40.914. Moments later, teammate Rosberg has a moment as he tries to avoid a piece of debris.

Twenty-two minutes into the session, Webber goes ninth (40.760) as his Red Bull teammate Vettel heads down the pitlane. Senna is the only other driver that hasn't yet posted a time.

On his second flying lap, Vettel goes second with a 39.983 while Webber remains eighth with a 40.267.

A 39.728 sees Vettel go quickest as Massa spins on the approach to Turn 8, the Ferrari stranded in the middle of the track and bringing out the red flags. On the pitwall Rob Smedley's shake of the head says it all.

After a five minute break the session resumes with 54 minutes on the clock.

Alguersuari is the first driver out, he is also the first driver to run on the option tyre. Elsewhere, Webber improves to fourth with a 39.905.

Form out of nowhere, Rosberg produces a 39.650 to go quickest, only to be demoted moment later by Webber (39.532) who goes quickest in the final sector.

A 39.635 sees Vettel make it a Red Bull 1-2, the Milton Keynes outfit clearly not prepared to give up here without a fight.

Next time around, Vettel goes quickest (39.379) having gone quickest in the middle sector. Felipe Massa watches from the pitwall, his session over.

Glock's session is over, his Virgin grinding to a halt at Turn 12 and subsequently being winched away.

Hulkenberg (currently seventeenth) is on track on option. However, he fails to improve.

Alonso (option) goes quickest with a 39.283 as Massa (also option) heads down the pitlane, his team having somehow got the car back to the pits.

Petrov has to put his car in reverse after spinning at Turn 14, the Russian currently thirteenth, around 0.8s off his teammate's pace.