Luxury car-maker Porsche says the Northern Territory Government is running a “nanny state” after open speed limits were partly removed.

Drivers have been able to drive as fast as they want along parts of the Stuart Highway between Alice Springs and Tennant Creek, but new Chief Minister Michael Gunner is now implementing a pre-election promise of removing the unrestricted speed zones.

German car-maker Porsche says it will damage the NT's reputation.

“We've done a pretty good job of killing off the local car industry, the manufacturing of local cars in Australia, and now it seems the Northern Territory Government's doing its best to deter international car companies from coming to Australia to spend money and invest in the local economy,” Porsche's director of public relations Paul Ellis said.

Porsche uses the roads to test its cars and shoot some of its advertisements.

“It's an entirely politically motivated decision,” he said.

“There's no logic. There's no sound reason behind it.”

Mr Gunner said it was all about safety.

“We have made that decision for safety, on the basis of advice from doctors,” he said this week.

“Speed does not kill, bad driving kills,” Mr Ellis said in response.

“It's just a shame we've taken a nanny state approach.”

Labor’s plan has the support of the Royal Australasian College of Surgeons (RACP), who say higher speeds bring a greater risk of injuries from road accidents.

Car companies may still be able to apply to do testing at any speed.

“We can allow for permits for testing in the Territory,” the Chief Minister said.

“This has happened in the past with Ford, Bentley and Top Gear.”