The planned camp would be accessed via helicopter, which has incensed certain elements of the local community, as well as conservationists. The site of the proposed camp is in the Walls of Jerusalem National Park.

Despite the Central Highlands Council voting to reject the plan in February, proponents Daniel and Simone Hackett, who run the RiverFly1864 fishing tour company, have lodged an appeal against the decision with the state's Resources Management and Planning Appeal Tribunal.

The Parks and Wildlife Service boss John Whittington has applied to join the Hacketts' appeal, while the planning tribunal has heard that the state's Solicitor-General has provided Attorney-General Elise Archer with advice that the council may not have had the legal right to block the proposal.

On Saturday, the Fishers and Walkers Against Helicopter Access held a rally on Parliament Lawns in Hobart to express opposition to any Lake Malbena development.

The group describes itself as apolitical, however two of the speakers were sitting members of the Federal Parliament - Clark independent MHR Andrew Wilkie and Tasmanian Greens Senator Nick McKim.

FAWAHA southern representative Emily Handley said she was "pleasantly surprised" to see the support for the group's cause, noting that at least 100 people were present at the rally.

"It was the first time we'd held something like this in Hobart," she said.

"There aren't as many recreational fishers in Hobart as there are elsewhere."

Ms Handley said the rally was about "making a stand for people in regional areas".

In a statement, Mr Wilkie described the Lake Malbena proposal as "manifestly inappropriate" and said it should be "resisted" by the federal and state governments.

Senator McKim told the rally the Tasmanian Wilderness World Heritage Area was "precious" and that "we've got a [state] government that might know the price of everything, but they know the value of nothing at all".

Ms Handley said state Liberal MHA Guy Barnett apologised to the group that he wouldn't be able to attend, while Braddon Labor MHR Justine Keay gave a statement of support for the FAWAHA and Tasmanian Labor Senator Anne Urquhart wrote to the group to detail her work with Senator McKim to improve the Environment Protection and Biodiversity Conservation Act.