Conservationist Bob Brown believes a ban placed on protesters from his foundation by Tasmania's workplace safety regulator flies in the face of Australia's constitution.
The Bob Brown Foundation on Monday filed legal action in Hobart Magistrates Court against the ban, issued last week by WorkSafe Tasmania.
The edict prevents activists from the foundation from protesting in the state's forests unless they abide by certain workplace health and safety regulations.
"I think the prohibition is illegal and unconstitutional," Dr Brown said outside the court.
Lawyer for the foundation, Roland Browne, believe the regulator doesn't have the power to issue such a broad-ranging edict.
He told media it also fails to comply with the relevant act and the edict is contrary to the constitution because it stops communication about government and political matter.
The foundation has requested an urgent court hearing.
"In the meantime the peaceful protest will proceed to defend Tasmania;s beautiful forests, not least the Tarkine," Dr Brown said.
"We will stop protest action when they stop destroying Tasmania's World Heritage value forest and its wildlife."
Several Bob Brown Foundation protesters were arrested earlier this month after chaining themselves to machinery and gates at forestry operations in the northwest Tarkine rainforest.
WorkSafe has previously indicated the protest ban is about protecting the safety of activists and workers, although the regulator says it is unable to comment specifically on the legal action.
It claims protesters have engaged in high-risk construction work and are at risk of falling from wooden tripods and platforms.
The regulator also has issues with the risk of protesters falling or being crushed when climbing machinery.
Australian Associated Press