Attempts to transform Kosciuszko National Park into a major year-round tourist destination have been slammed as an attempt to undermine 70 years of conservation in the southern NSW jewel.
In an open letter published on Friday, a group of conservationists pleaded for more time to examine the amendments to the Kosciuszko National Park Plan of Management and a Special Activation Precinct Plan.
The group included ex-Greens leader Christine Milne as well as academics, environmentalists and civil society leaders.
The group argued the plan would increase on-park accommodation by 60 per cent, clear habitat for car parks, permit some helicopter access into resorts and allow commercial vehicles on walking tracks.
The plan would also involve the redevelopment of the town centre for the Snowy Mountains' main visitor hub Jindabyne.
Gary Dunnett, chief executive officer of the National Parks Association of NSW, said the public exhibition period for the plans had not been long enough and at least an extra 60 days were required.
"We just need more time to digest what's proposed," he told AAP.
Mr Dunnett said the plan for the park would begin to unwind the conservation-centric focus of authorities stretching back to the 1940s.
It would further compound the stresses induced by climate change, bushfires and feral species on the 6900 sq km park.
"We've had this extraordinary success over the 70 years of that landscape slowly getting the chance to recover," Mr Dunnett said.
"(This) turns it on its head - it says, you've had your crack at ecological restoration, now it's time for lots of commercial development."
NSW Deputy Premier John Barilaro has previously vowed the government would tread carefully on any development plans for Australia's alps, saying it didn't want to lose "what is so special" about the region.
Labor environment spokeswoman Penny Sharpe this week wrote to Environment Minister Matt Kean demanding the NSW government continues to prioritise conservation activities in the park.
"I ask that you take immediate action to ensure that adequate planning for Kosciuszko National Park can be undertaken with conservation at the centre of consideration of how this iconic alpine park will be managed for the next 40 years," Ms Sharpe wrote in her letter.
"The current consultation period must be extended to at least the end of October to give the local community the time to have genuine input."