Casey Stoner threatens to walk away over future MotoGP rules

Series promoter Dorna is heavily pushing the new Claiming Rule Teams system, which allows elements of modified production machinery.

In addition to several new teams stepping up to MotoGP next year under the CRT regulation, a number of current satellite squads are expected to ditch their pure prototypes to run CRT bikes, amid suggestions that the system could form the basis of MotoGP's future.

But Stoner said he felt a move too far towards a lower-technology formula would be the wrong choice for MotoGP.

"I think if we kill prototypes then we may as well be racing touring cars," he said. "It's no different to this. It'll definitely take everything out of the racing for me.

"I won't find the same interest to the point where you can maybe get a street bike, put a different chassis on it, a bit of suspension and this and that, and have a competitive bike.

"This [prototype rules] is the way it's been for so many years. There have been a few things recently about costs, which have definitely increased, and the amount of personnel needed to run these bikes. They're definitely more complicated than the old 500cc.

"But if it does change like that [to more production-based rules] then it's definitely going to be disappointing for me and I don't know if I'd want to be a part of it."

Yamaha's Ben Spies said he was also concerned about the prospects of a CRT-based future for the championship, though he acknowledged that the global financial system might force radical change.

"The way the economy's going, I hope I have a job in 2013, so I'm not worried about a CRT bike right now, that's for sure," he said. "But I'm not the biggest fan of it."