PORTLAND, Ore. — Lawyers for Ammon Bundy revealed plans to contest the authority of the federal government to prosecute their client for the takeover of a national wildlife refuge in Oregon.

Attorney Lissa Casey says in court papers that a forthcoming motion to dismiss the case will challenge the federal government’s assertion that it has ownership of the Malheur National Wildlife Refuge.

“The federal government relinquished the land when it was previously deeded and homesteaded, thus relinquishing jurisdiction,” Casey wrote.

Moreover, she said, the defendant intends to argue the government largely lost the right to own land inside Oregon once statehood was achieved.

The U.S. Supreme Court, however, has twice ruled that the government owns the land in question, presenting an uphill climb for the attorneys.

“We look forward to Ammon Bundy’s attempt to re-litigate 200 years of jurisprudence regarding the property clause, and the 1935 Supreme Court case that specifically established the American people’s ownership of the Malheur National Wildlife Refuge,” Jennifer Rokala, executive director of the Center for Western Priorities, said in a statement posted on the organization’s website.

Bundy and his followers seized the refuge Jan. 2 in a protest over federal land policy and the imprisonment of two local ranchers who set fires. A Jan. 26 traffic stop led to Bundy’s arrest and the shooting death of occupier Robert “LaVoy” Finicum.

A September trial has been scheduled for Bundy and the more than two dozen others who took part in the takeover that eventually ended in February. Bundy pleaded not guilty to conspiracy and gun charges.

Bundy’s lawyers presented the basics of their argument while asking a federal judge to extend the deadline for filing motions to dismiss the case. Casey said evidence must be produced regarding chain of title and actions or inaction of the government.

“Given the complexities of the evidence involved, it is not a simple legal argument that can be briefed and expedited for the Court,” she wrote.

Bundy’s views on the federal government should get an extensive airing at his upcoming trial. Though often described as anti-government, Bundy has said that’s not the case. He said the federal government has a responsibility to protect the states from outside invaders. When critics pointed out that his company got a $530,000 loan through the Small Business Administration, he noted that he’s only opposed to federal policies that go against the people’s will.

Bundy, meanwhile, is due to return to a Portland jail early this week. He was flown to Las Vegas nearly two weeks ago to make a court appearance on charges related to an armed standoff at his father’s Nevada ranch in 2014.