Gov. Steve Bullock on Monday filed suit against the Bureau of Land Management and its acting director William Pendley, claiming he was violating federal statute by continuing to make key land-use decisions while lacking Senate confirmation.

The suit, which names both Pendley at the BLM and Interior Secretary David Bernhardt, alleges that Pendley is in violation of both the U.S. Constitution and the Federal Vacancies Reform Act.

“I’m taking this action today not just to block William Perry Pendley’s further illegitimate oversight of the Bureau, but also to ensure that this unconstitutional abuse of executive powers does not become commonplace under any administration in the future,” Governor Bullock said in a statement.

Montana Democrats in June voiced opposition to Pendley’s nomination to head the BLM, saying he has supported the sale of public lands and lobbied on behalf of the oil and gas industry. They also suggest he has violated other federal laws and the trust of Western governors.

Pendley has served in an acting roll since last summer and has drawn the ire of environmental stewards and public lands advocates ever since.

According to Bullock's suit, federal law prohibits acting directors from serving while their nomination is pending. The lawsuit seeks to bar Pendley from illegally performing the duties of director until the Senate has confirmed his nomination.

“During Pendley’s unlawful tenure, the BLM has interfered with Montana’s collaborative efforts and public access priorities,” Bullock said. “This decision-making by unconfirmed federal officials stands to create long-lasting and irreversible injury to our state’s lands, economy, and wildlife.”

Sens. Jon Tester and Jacky Rosen, D-Nevada, on Monday also announced a press call with various outdoors groups and Native American tribal representatives to discuss Pendley's opposition to public lands and his lack of confirmation.

Among other things, Bullock said the BLM violated the law when it abandoned a bipartisan agreement with Western governors that prioritizes oil and gas leasing outside of sage grouse habitat, placing Montana's economy at risk.

Bullock also contends that the BLM continues to violate federal law and its own requirements to consider the protection of areas that have special fish and wildlife, archaeological and primitive recreational values in their Resource Management Plans. The plans guide land management decisions over time.

Bullock said the Constitution requires the president to nominate and the Senate to confirm heads of significant federal agencies.

“In defiance of this constitutional tenet, BLM has been run by a series of acting directors for the entirety of the Trump Administration—most recently through the recurring Acting Appointment of William Perry Pendley for over one year,” Bullock's statement read.