Half the field are on the yellow-walled soft tyres as Nico Rosberg improves further with 1:49.385. He is three tenths of a second ahead of Lewis Hamilton, with four-time Belgian GP winner Kimi Raikkonen third and Marcus Ericsson fourth. 

Just over 50 minutes of the session left.

Marcus Ericsson's quick lap was done despite a pesky bird dropping an, ahem, deposit on to his car. Luckily it appears to have ended up on the camera, rather than his visor.

Marcus Ericsson is up into P1 but only for a second as Nico Rosberg's first run on the softs sees him become the first driver this weekend to dip below 1:50, posting a 1:49.385.

Nico Rosberg and Marcus Ericsson follow Sebastian Vettel's lead by switching to softs.

Sebastian Vettel straps on the soft compound tyres and storms to the top of the timesheet with a 1:50.940.

Meanwhile, stewards announce that they are investigating an incident between Nico Hulkenberg and Romain Grosjean at Turn 18.

James Allen
BBC Radio 5 live F1 commentator

Crikey! Even my stomach knotted as Felipe Nasr jumps on the brakes to avoid a collision in the pitlane as Daniil Kvyat's Red Bull is released early. A collective 'wooah!' from the BBC commentary box, but a good save by Nasr.

The Red Bulls are splitting the Mercedes at the moment as Daniel Ricciardo's first flyer of 1:51.080 sees him jump into P2.

Meanwhile, Pastor Maldonado is trapped into his seat and waiting patiently to be released...

Twenty minutes into the session and everyone has been out apart from Pastor Maldonado. How long before Lotus get him out?

Nico Rosberg slots into P2 with his first timed effort, a 1:51.082, with Lewis Hamilton 0.288s slower and he goes third fastest.

Rosberg then improves slightly to go fastest of all with 1:51.052.

Andrew Benson
Chief F1 writer

“As you will know if you were watching first practice, Pastor Maldonado had a crash. I know, what a surprise.

"Anyway, the car was quite badly damaged in the off, in which he collided with the wall having lost control on the exit of Malmedy. The right-hand side was quite badly damaged and consequently was not ready for the start of the session. 

"Team-mate Romain Grosjean, meanwhile, is running a new front wing design on his car. There is only one. Maldonado was not allowed to use it in the morning.”

Sebastian Vettel sets the very early pace with a 1:52.606, a time that unsurprisingly does not last long as the benchmark, with Daniil Kvyat posting a 1:51.135 to top the pile.

Romain Grosjean is about to be sent out with a new front wing on his Lotus.

Hmmm. I wonder why Pastor Maldonado din't get to run with this morning...

Andrew Benson
Chief F1 writer at Spa

“Ferrari’s Sebastian Vettel headed off on his summer break after his second victory of the season in Hungary saying his title hopes had never been over, although he did add that he would ‘try to make the impossible possible’. 

"Three and a bit weeks to think about it has not made him any more confident. ‘If you look at the maths,’ he said earlier this week, ‘I don't think it takes a genius to see how many points we can still score and how many points we are behind. But for sure we also know that being realistic that it will be difficult. 

"'If we have the opportunity to turn things around like in Hungary then we have to go for it. If we have the opportunity and we don't use it then it's down to us and our mistake. But if you look at the races so far, we had two opportunities that we used. But the advantage is still there. It doesn't just disappear.’”