Concern is growing that road rage on the race track is turning Britain's most popular national championship into a scrapyard for wrecked cars.

Bumper-to-bumper dicing has always been a feature of the British Touring Car Championship and the prospect of close competition will fill Silverstone on Sunday, when seven drivers go into the penultimate meeting of the series still in contention for the title.

But Tim Harvey, the former champion who now commentates for ITV television, said: "Nobody likes to see all those beautiful machines with hammers being applied to them and panels being replaced. It is up to the officials to decide if there is too much contact. You have to say that on occasions it does go too far."

Jason Plato, who has won five of the last nine rounds in his SEAT, believes it went too far a fortnight ago at Knockhill - where a battle with title rival Tom Onslow-Cole saw him smash into the barriers.

"I have no issue with being beaten properly," said Plato. "I do have an issue with this kind of s**t. If it was anywhere near on purpose then it was bang out of order."

But Onslow-Cole shrugged off the incident, saying: "It's just one of those things that happens when you're battling so hard."

Italian ace Fabrizio Giovanardi leads the title chase from Plato and BMW's Colin Turkington.