British GT Championship G4 class leader Jamie Stanley and Christian Dick will face their toughest opposition of the season in the two-hour Silverstone race, with several new entries expected to bolster the class for the 15 August race.

Alongside the pair's Speedworks Ginetta and their fellow regular – the Chris Bialan/Simon Mason Piranha Motorsport Lotus 2-Eleven – the incomers include some experienced names, tempted to the series by the longer race and the double points on offer for the championship.

Chad Racing will return to G4 with the KTM X-Bow that won the class in both races on its debut weekened at Rockingham. However, Michael Mallock, one on the drivers that day will spend his Silverstone week on the Chad Racing pitwall, helping oversee the entry. His place in the drivers seat, partnering the car's owner Athanasios Ladas, will be taken by Dutchman Kevin Veltman, an experienced racer in the GT4 European Cup, where he campaigns a BMW.

Making their own debuts at Silverstone are two more Ginetta G50s – the car already a popular choice in the class this season.

Century Motorsport will introduce a second car alongside regular pairing Nathan Freke and Vibe Smed. The second car will be driven by brothers Benji and Freddie Hetherington, both familiar names to Ginetta fans, running for the team in the BTCC supporting G50 cup this season. The team has already confirmed it will also run a car for the brother at the following round at Snetterton in late August.

“They [the Hetheringtons] have never tackled a race this long but they are both very quick drivers,” said team principal Freke. “The Ginetta may not be the quickest car in a straight line but we have a good set up and they will be running without any success ballast. They should go well.”

Having finished third in the GT4 class points standing last year Stark Racing will return to the series at Silverstone, drivers Ian Stinton and Paul Marsh joining up in the car to reprise the partnership that won at Knockhill last year – the team's only class victory of 2009, Stinton hopeful of repeating “the trick” at Silverstone this year.

G4-spec machinery is also likely to be running in the Invitation class, with another Ginetta G50 – this one prepared by Reflex Racing GB – for another family driver pairing, Essex-based father and son Peter and Matt Smith.

The pair, who have raced in Ginetta G20s previously admit the outing at Silverstone is a taster exercise for the pair, running in a car in allegiance with the British Kidney Patients Association.

“I was diagnosed with kidney cancer 10 years ago and decided to take up racing while I could,” explains Peter. “We are out to celebrate the fact that I am still here racing, and to enjoy ourselves and help raise awareness for kidney patients. We have always wanted to do some longer-distance races and this is a good opportunity to test the water.”