The question of whether wild horses should be allowed to roam free in national parks has long divided Australians.

But that passion is now rising again, with just days left in the public consultation period for a contentious brumby management plan for New South Wales.

A group of scientists has written to the state's environment minister, calling for the extermination or removal of all horses in national parks, including Kosciuszko.

But supporters of the brumbies' right to exist say they're now part of the highland's cultural heritage, and their effect on the environment is exaggerated.

Professor Jamie Pittock spoke to ABC Radio National.