Teams' request for new tyres for Belgian Grand Prix denied

A number of drivers are understood to have suffered blistering to their front tyres in qualifying - and with all those who reach Q3 having to start the race on the same tyres they used for the pole shoot-out, some could be exposed to trouble in the race and require an early stop for new rubber.

There was lobbying of both Pirelli and the FIA from some teams to try and be allowed to replace the blistered sets - claiming that they were damaged enough to be allowed fresh ones for the start.

However, the FIA has stood by its stance that tyres can only be replaced if damage to them - which can include blistering - has been caused accidentally. If a set-up choice resulted in teams blistering their tyres, then that is not sufficient reason to be allowed replacement sets.

As a precautionary measure, Pirelli flew in 17 new front tyres overnight - to add to the three spare tyres that were already in the Spa paddock.

This would ensure that if the FIA agreed teams could use new tyres there were enough sets for the top 10 drivers who have to start on their qualifying rubber. Such approval was not forthcoming, though.

The issue is believed to particularly affect the Red Bull Racing drivers, with both Sebastian Vettel and Mark Webber understood to have suffered blistering to both their front tyres.

However, Lewis Hamilton is also believed to have suffered blistering on one of his front tyres, as did Scuderia Toro Rosso's Jaime Alguersuari.

Tyre blistering is normally a result of excessive tyre temperature, and one of the contributing factors to it rearing its head at Spa is believed to be the camber settings that a number of teams have been using - which may have gone outside the recommended parameters laid down by Pirelli.