Rapax driver Tom Dillmann confirmed this week that he would not be competing in the British round of the GP2 Series this weekend.

"I'm going to miss the British GP," he announced on his Twitter page. "Disappointed to confirm that I won't race in Silverstone," he added.

The decision to stand Dillmann down seems to be related to financial considerations within the team, and follows rumours that swept through the European press two weeks ago that Dillmann was also about to miss the Valencia event in favour of Dutch driver Dani?l de Jong.

In the end Dillmann competed in Valencia after all, after his regular Rapax team mate Richard Teixeira was taken ill. But there looks to be no second reprieve for the 23-year-old Frenchman this weekend, and the Bahrain sprint race winner will instead be watching from the sidelines at Silverstone.

Dillmann appeared to confirm that the team decision to replace him this weekend was money-related when he thanked his fans for their support. He added: "Sad but that is the dark side of autosport ... I will keep fighting believe me, I wouldn't be at this level otherwise."

There don't appear to be any other driver changes for this weekend's GP2 races, which will see the teams be provided with five sets of tyres - three prime, two option - for the race weekend for the first time

"The latest GP2 regulations will allow the drivers to gain more experience of our tyres and how best to use them," said Pirelli's racing manager Mario Isola. "This is a rule that will remain in place for the rest of the year. It's going to be interesting to see which drivers and teams manage to make the most of the new regulations straight out of the box at Silverstone."

Isola also referred to the heavy rain and showers forecast to hit this weekend's sessions. "The weather conditions at Silverstone can be very variable, which could clearly affect the set-up of the cars and the behaviour of the tyres from one session to the next."

Coloni's Stefano Coletti said that far from being concerned about the rain, he was hoping that it would boost his efforts this weekend.

"The possible rain does not worry me much as it can be an ally of mine considering that I have always been at ease on wet condition," he said. "All the British tracks have a particular flavour and the atmosphere that one can breath at Silverstone during the F1 weekend is probably the real soul of motorsport."

The GP2 action at Silverstone starts with the 30-minute free practice session on Friday morning at 11.55am between the two F1 Free Practice sessions, and is forecast to be hit by heavy rain. There are hopes that the weather will be much clearer for the qualifying session later in the day at 4pm.

The 29-lap feature race 1 will take place on Saturday afternoon at 2.40pm after the F1 qualifying session, while the shorter 21-lap sprint race 2 is on Sunday morning at 9.40am. All the GP2 sessions are scheduled to be shown live on Sky Sports F1.