Asserting that Drakes Bay Oyster Company's legal case raises no questions of "exceptional importance," Interior Department attorneys Monday urged a federal appellate court to reject the company's latest appeal of the loss of its operating permit.

"There is no broader question of law here that requires review by the full Court," said the 15-page brief filed in support of former Interior Secretary Ken Salazar's decision not to renew the oyster company's permit to harvest shellfish in the Point Reyes National Seashore.

The brief also disputes arguments by the oyster company's allies — including the Sonoma County Farm Bureau — that sustainable food production should be allowed in Drakes Estero, a 2,500-acre Pacific Ocean estuary.

The Point Reyes Wilderness Act of 1976 "unambiguously prohibits most &‘commercial enterprise' within wilderness," the government brief said.

A federal district court judge and a 9th Circuit U.S. Court of Appeals three-judge panel have rejected the oyster company's case, which asserts that Salazar's decision in November 2012 was "arbitrary, capricious and an abuse of discretion."

Company owner Kevin Lunny now seeks a rehearing before 11 judges from the 9th Circuit. To get that hearing, a majority of the circuit's 28 judges must agree to accept it.

Lunny's company sells $1.5 million a year of oysters cultivated in the estero's clear, cold waters.

Several teams of lawyers have handled Lunny's case for free since he began fighting the National Park Service's shutdown order a year ago. With each appeal, Lunny has retained the right to continue doing business on the estero shoreline.

Interior Department attorney J. David Gunter II declined to comment Monday on the agency's brief.

Amy Trainer, executive director of the Environmental Action Committee of West Marin and a former environmental lawyer, said the brief "handily dismissed" the oyster company's arguments for a rehearing.

Peter Prows, a San Francisco attorney representing Lunny, said the government had made "a remarkably weak response" to the company's brief submitted in October.

If the rehearing is denied, Prows said the company likely would not give up.

"I don't see any reason why we wouldn't take it to the Supreme Court," he said. "It's a bigger issue than just the oyster farm."

The government's latest brief asserted that the case is a "unique factual situation" that applies solely to the oyster company's permit, originally granted in 1972.

The 9th Circuit is under no deadline to rule on the request for a rehearing and could take two to four months to decide and up to a year more to hear and decide the case, Prows said.

Trainer said it would be a "travesty" to allow the oyster company to continue in business that much longer.