Ninety-one organizations representing conservationists, sportsmen and wildlife advocacy groups sent a letter to U.S. Secretary of the Interior David Bernhardt on Tuesday requesting that he fire William Perry Pendley, the acting director of the Bureau of Land Management.

“Pendley holds views that are antithetical to the BLM’s mission to manage public lands and resources on behalf of all Americans. In fact, Mr. Pendley has called for selling off public lands,” the letter states.

The organizations signing the letter include The Lands Council, Western Wildlife Conservancy and Earthjustice. They referenced the planned move of BLM employees to the Grand Junction headquarters, and an agency directive that those who do not relocate may be out of a job.

“This unwarranted (and potentially illegal) threat of termination is demoralizing career employees at the same time he is undermining the operational effectiveness of the agency,” the letter states.

RELATED: Pendley: BLM move to Grand Junction could be ‘traumatic’ for some employees

Pendley, per the BLM’s website, is BLM’s deputy director for policy and programs, who is only “exercising the authority of the director.” He has not been confirmed by the U.S. Senate, nor is he relocating to Grand Junction.

Protesters are expected Thursday beginning at 10 a.m. outside the new BLM office at 760 Horizon Drive in Grand Junction, according to a media advisory Tuesday from the Clean Water Fund and other groups.

Critics of Pendley have raised concerns ranging from conflicts of interest with his previous legal work, an anti-public lands attitude, and a suspicion that the move to Grand Junction is designed to force out those with institutional knowledge at the agency.

“For this group of environmental extremists to call themselves sportsmen and conservationists is as laughable as this letter,” an Interior spokesperson said Tuesday. “Mr. Pendley brings a wealth of knowledge and experience to the Department and is committed to carrying out the Administration’s priorities for the betterment of the American people.”

Editor’s note: This story has been updated with a statement from the U.S. Department of the Interior and information about planned protests Thursday.