The Trump administration has asked the Supreme Court to lift a pause on a border wall project in the Big Bend region of Texas.

An emergency appeal filed on Wednesday asks the justices to undo a lower court decision that halted construction, a ruling that dealt a setback to one of President Donald Trump’s signature projects. The administration has been pushing construction of the wall and other infrastructure along the border from the Pacific Ocean to the Gulf of Mexico.

In Big Bend, however, it has faced resistance from ranchers, residents, business owners and environmentalists. They argue the projects are a waste of money in an area of historically low illegal immigration, and that construction could harm the region’s scenic landscapes.

Opponents have brought numerous lawsuits seeking to stop the project, which in Big Bend consists of a mixture of walls, vehicle barriers and surveillance technology.

The case the government is now contesting centers on sweeping waivers signed by the secretary of Homeland Security. Those waivers allow U.S. Customs and Border Protection to bypass environmental and other regulations that would otherwise slow down construction of such a major project.

The government argued that the Big Bend sector is an area of high illegal entry. It said legislation dating back to 1996 explicitly gives the secretary these far-reaching powers as necessary to build physical barriers or roads near the border to stop people from crossing illegally.

Opponents disagreed, arguing that Congress gave that power to waive regulations specifically in areas of “high illegal entry.” They said Big Bend, a remote and rugged region, doesn’t fit that description.

Judge Kathleen Cardone sided with the opponents. On Oct. 2, she ordered the government to stop construction across the roughly 500-mile project area while the case plays out in the courts. The ruling was a major victory for the bipartisan opposition.

“The Court finds that Plaintiffs are likely to succeed on the merits of their major questions doctrine claim that the Big Bend Waivers were issued in excess of the Secretary’s authority,” she wrote.

Trump has long vowed to build a border wall along the roughly 2,000-mile length of the southwest border. Last summer, Republicans in Congress allocated Homeland Security $46 billion to finish the project.

The finished project will be a mixture of 30-foot-tall steel bollard walls, vehicle barriers and surveillance technology. Opposition in Texas’s Big Bend region had been brewing for months.

It escalated in August when bulldozers were spotted clearing land in Big Bend National Park. The preliminary injunction filed by Cardone stops construction there as well as land up and downriver from the park that is owned by private landowners or the state.

The government has argued that if this region is one of the only areas left without a wall or other border infrastructure, illegal immigration could end up funneling to the Big Bend. Opponents have countered that other forms of infrastructure such as drones or surveillance towers are just as effective and a lot less expensive than the wall plans.