Already having to deal with excessive degradation as a result of the unusually high temperatures, and fears that the supersoft tyres might last just a couple of laps tomorrow, drivers face another challenge in terms of the high tyre pressures mandated by Pirelli.

Ironically, it was the failures here last season that led to Pirelli, in conjunction with the FIA, setting a minimum tyre pressure for each event.

However, drivers fear that the pressures this weekend are too high, and are making the cars almost impossible to control.

"The pressures are unbelievably high," warned Jenson Button, "you can see that by how slow we drive around on the way to the line. Most cars are not going full throttle at all on their way to their qualifying laps, they are not braking, they are not pushing the tyre at all. They start their lap and get to Turn 1 and the tyres work.

"It is amazing what we have to do to get these tyres in the working window," he continued. "If you push on the out-lap then they are done by Turn 3, blistering and overheating. What we have to do is crazy. I've never had to do this before in my F1 career."

"With these tyres the way they are, which are a bit of a mess, it's going to be tough out there for everyone," added Lewis Hamilton. "The pressures are so high, I've never seen anything like it in my whole racing career. That doesn't help, plus it's very hot, and with those pressures we get blisters. There is not much you can do to save the tyres from blistering and overheating."

"It is the pressures," insisted Button, obviously it is not helped by the temperatures but we go to hot countries and I think Pirelli know that.

"We are in a position at the moment with the tyre where you cannot push the car. You are just rolling around the whole time with the tyre, it's a shame. Hopefully with the new tyres next year that won't be the case because it is not a nice feeling at the moment."

Check out our Saturday gallery from Spa, here.