SAN FRANCISCO (CN) – Attorneys for the Sierra Club, a consortium of states and the U.S. House of Representatives argued President Donald Trump and his administration overstepped their constitutional authority in using Pentagon funds to build a border wall during a hearing at the Ninth Circuit in San Francisco on Tuesday.

“What is actually happening here is that there are individual parcels of land within 20 miles of each other and the government is calling it a military installation,” said Josephine Morse, an attorney for the U.S. House of Representatives, during the hearing Tuesday. “The government is using a catchall phrase to allow for a limitless interpretation that goes against Congress’s intent.”

The interpretation at issue is the federal government’s reading of a law that governs the construction of military facilities.

The U.S. Department of Justice says the law allows the U.S. Department of Defense to reshuffle its monetary priorities in the event of a national emergency, meaning U.S. Secretary of Defense Mark Esper used proper discretion when he used the money to build a section of wall near military installations in Arizona and California, near San Diego.

“There is nothing in the context of this statute that would constrain the authority of the Department of Defense in times of national emergency in the manner the district court has suggested,” said Thomas Byron, an attorney arguing on behalf of the Justice Department.

But the plaintiffs said such an argument is nonsense, particularly because Congress debated the construction of the border wall and specifically and willfully left it out of the budget.

The plaintiffs say the executive branch cannot defy the congressional control of the power of the purse by concocting some fake national emergency to justify the military construction of what amounts to a civilian project.

“The government’s view is such a radical departure from how Congress set up our immigration system,” said attorney Dror Ladin, arguing on behalf of Sierra Club.

Ladin said Congress purposefully set up the U.S. Department of Homeland Security as a separate entity from the Department of Defense and was clear about how it wanted to fund border control projects through that apparatus.

But the Trump administration said it had to send military personnel to the border last year during an influx of individuals from Mexico and Central America attempting to cross the border. The government further claims the construction projects in proximity to the two military installations in California and Arizona will contain cameras and other devices designed to help the military assuage what the administration believed was a national emergency.

“The construction will provide local surveillance, aerial operations support and allow more efficient deployments in a more limited amount of areas, whereas previous resources were stretched more thinly,” Byron said.

A federal judge already ruled against the Trump administration in this regard, granting plaintiffs an injunction to stop the construction, but the Justice Department is asking the Ninth Circuit to reverse the lower court decision.

The argument was conducted before a three-judge panel comprised of U.S. Circuit Judges Daniel Collins and Kim McLane Wardlaw, and Chief U.S. Circuit Judge Sidney Thomas.

Wardlaw and Thomas were both appointed by President Bill Clinton. Collins was appointed by Trump.

Often judges will tip their hand about which way they’re leaning by their line of questioning or on which elements of the arguments they chose to focus, but such was not the case during this hearing.

Mostly the judges kept silent as the attorneys made their case.

Thomas thanked the attorneys for making the trip despite the coronavirus outbreak in the United States. He also hinted the court was considering scaling back in-person hearings significantly in the coming days.

“In the coming months, we are going to make adjustments to our upcoming panels — on a case by case basis — to accommodate attorneys who want to appear remotely on account of the ongoing coronavirus situation,” he said.

The judges took the present matter under submission.