Honda duo struggling with tyres

"Whilst it is great to be back at Spa, one of the most challenging and enjoyable circuits of the season, we did have a difficult time in free practice today," said Button, who could only manage the 17th fastest time with his Honda.

The Briton admitted he had problems to get the tyres up to working temperature, but was hopeful there was still something that could be done for tomorrow.

"It was very hard to get heat into the tyres in the cool and damp conditions, which meant that I had little front grip which is particularly difficult here given the cambers in the corners. We also struggled with understeer," he added.

"However we have a lot of data from the test last week and from our running today, so we will study this overnight and see where we can improve before qualifying."

Teammate Rubens Barrichello had the same problems, the Brazilian saying his car's handling was very unpredictable.

"I was happier with the balance of the car in the afternoon session, however we struggled a lot with the rear end which was very unpredictable throughout the day," said Barrichello, 18th fastest.

"The rain this afternoon did not help as we lost some track time but this was the same for everyone. At the moment, it looks like this track and dry conditions will not favour us, so we will be hoping that it rains heavily over the weekend."