The rapid growth of GT4 over the past two seasons has left many British GT Championship regulars turning their attention away from GT3, raising questions about the future of the top class.

Last weekend’s double-header at Snetterton had just ten GT3 cars alongside 17 GT4 entries, with the latter continuing to benefit from the rising costs of GT3 that are forcing drivers, teams and manufacturers to look further down the field.

McLaren is amongst the names absent from the top class this season, and McLaren GT Sporting Director Bas Leinders explains why his brand is concentrating on its 570S GT4 in British GT.

“The reason we have the GT4s is because they are very good cars, it’s a good championship and GT4 is on the up, so it is important that McLaren is represented in the best possible way,” he told Sportscar365.

“There will be very good competition in the future – there already is now – but with Audi, BMW and Mercedes stepping up, it will only get more entertaining.

“GT4 is very competitive, with a lot of cars, a lot of teams and budgets are quite reasonable.”

Stuart Parker’s Team Parker Racing currently competes with a pair of Bentley Continental GT3s as well as the series’ sole Porsche Cayman GT4 Clubsport MR, and he says that the manufacturer interest in GT4 is a major attraction.

“The competition is getting better, and that’s because there are more manufacturers getting involved,” he told Sportscar365.

“You’ve got more product choice, so it’s not a two-horse race which it was a few years ago. Three years ago, you’d have a Ginetta or an Aston Martin, and that was your lot.

“Now, there’s the Porsche in the mix, the McLaren, and the Nissans are back.

“Next year is going to be really interesting because you’ve got all the big German manufacturers coming back in.

“It’s the age-old cycle – GT3 is going to die because it’s getting too expensive, and GT4 becomes the new GT3.”

A bold move from a GT3 regular saw Joe Osborne return to GT4 this season with Tolman Motorsport, something he says future-proofs his career.

“The most common thing people have said to me is, ‘Oh you’ve stepped down to GT4,'” he told Sportscar365.

“I can understand the logic, and GT3 is the headline class and the fastest, but if you now look at the grid, we’re two-thirds of it in GT4.

“Yes, it’s a step down in terms of speed, but in competitiveness, we have twice as many cars. OK, we don’t have the drivers like [Matt] Griffin, [Phil] Keen, and Jonny Adam, but there are some quick under-the-radar guys.”

Parker worries about the budgets required for GT3, meanwhile.

“The cost of GT3 is getting too much, and it’s getting to manufacturer levels of financial commitment,” he said.

“Private teams just can’t afford to pay the bills, and it’s gone from needing a wealthy person to a super-wealthy person.”

With a reduced GT3 entry last season and some manufacturers missing, Osborne was very vocal about his worries regarding the class’ downfall.

He admitted he didn’t expect GT3 to survive the off-season and that a 12-car full-season entry was far past his expectations for this year.

“I lost £50 on a bet with Benjamin [Franassovici, Championship Manager] that he’d have less than eight cars, and he proved me wrong!” he said.

“I’ve got no problems in being wrong if the series is healthy, but I still say that GT3 is frail. We’re now down to ten cars, and to me that isn’t a proper competitive championship.

“It’s hard to attract new blood, and I think GT4 is a lot more attainable, budget-wise, for these guys, and that’s why it has grown.”

Franassovici, meanwhile, assures that he is confident GT3 will remain part of the package next season, and that he is aiming for more cars than this year.

“We’re pushing for next year,” he told Sportcar365. “I think it’s very possible that we’ll have the same numbers next year, if not a couple more.

“There are a lot of young Silver guys who are stepping up. Ten is not what I want, so we’re pushing for more.”

The McLaren is part of the new generation of GT4 cars and Leinders was quick to praise the improvements made to the category in recent years.

“They are very nice cars now, and a few years ago they were not so nice race cars,” he said. “They’re enjoyable to drive and the speed has gone up.

“OK, the budget has gone up a little bit, but they are still only half the price of GT3 cars.”

While GT4 cars are still considerably more affordable than their GT3 counterparts, Osborne isn’t so sure that the arrival of new manufacturers next year will keep this true.

“GT4 will start its cycle of becoming GT3, which will ultimately get too expensive and then everything starts again,” he predicts.

“By the time I finish my career it will be GT86, because it’s just getting ridiculous.”