The Trump administration has ordered thousands of furloughed federal employees back to work without pay to inspect planes, issue tax refunds, monitor food safety, and facilitate the sale of offshore oil drilling rights.

The efforts in recent days illustrate how President Donald Trump is trying to limit the impact of the partial government shutdown and shield favored industries as the funding impasse thwarts the deployment of new aircraft, stock offerings and even craft beers. The Obama administration took the opposite approach in 2013 by erecting barricades around open-air monuments and largely closing national parks—then leveraging public anger to blame Republicans for halted government services.

Critics say the Trump administration is skirting federal law by continuing some functions amid the political stalemate between congressional Democrats and Trump over whether to fund a wall on the U.S.-Mexico border. A 149-year-old law bars agencies from spending money Congress hasn’t given to them, with only limited exceptions for “emergencies involving the safety of human life or the protection of property.”

“This administration is being creative in its ability to break the law and test the boundaries,” said Sam Berger, a senior adviser at the Center for American Progress who worked at the Office of Management and Budget under former President Barack Obama.

“They are really walking up to and past that line,” Berger said. “It’s clear they are making political calls, and they aren’t letting decisions be dictated by sound management, by the law or by really anything other than the next 10 minutes of news coverage and how they can win the day.”

The responsibility for prosecuting violations of the 1870 Antideficiency Act falls to the Justice Department—and no one’s ever been hauled to court to account for flouting the law. It’s not clear if anyone else would have standing to challenge agency spending and activities that continue amid a shutdown.

Paychecks for some 800,000 government employees have been halted amid the lapse in federal funding, including about 420,000 who have been forced to work anyway.

The Trump administration is calling back some 46,000 furloughed employees, according to an updated contingency plan released Tuesday, with many put to work issuing tax refunds even though the Treasury Department previously decided a shutdown would bar the activity.

The National Treasury Employees Union is suing the federal government for making those employees work without pay, arguing that forcing them to process tax refunds falls outside the scope of activities that should be permitted during a shutdown. A federal judge in Washington on Tuesday rejected a request by that union and other federal workers to issue a temporary order compelling the U.S. to pay its workers or let them take jobs elsewhere.

The plaintiffs included the Air Traffic Controllers Association, as work to patrol the skies continues amid the shutdown. The Federal Aviation Administration said on Tuesday it had “determined that after three weeks, it is appropriate to recall inspectors and engineers.” Those recalled workers will “perform duties to ensure continuous operational safety of the entire national airspace,” the agency said.

But they also may help the FAA begin processing a backlog of company applications to launch new flights and add planes to their fleets. American Airlines Group had been blocked from adding two newly purchased planes to its operations because safety inspectors must approve such additions. Southwest Airlines said on Monday it was delaying new service to Hawaii because it hadn’t been able to obtain FAA approvals necessary to fly long distances over water.

The Food and Drug Administration had briefly suspended some inspections before summoning furloughed employees back to conduct the work.

“With the support of our dedicated field force, we’re recalling hundreds of furloughed colleagues to conduct inspections of high risk food facilities and other entities,” FDA Commissioner Scott Gottlieb said Monday on Twitter. Gottlieb said the inspectors will be working on “mostly unpaid” assignments, as about 150 of the roughly 400 newly recalled workers seek to ensure companies are complying with federal standards for making, processing and packing food.

The Interior Department is now clearing the way for previously furloughed workers to help sell drilling rights in U.S. coastal waters, as 11 personnel are being temporarily recalled to prepare documents necessary for auctions of Gulf of Mexico expected in March and August. The Bureau of Ocean Energy Management said it is tapping “carryover” funding from fiscal 2018 to facilitate the activity, with the employees exempted “for only the amount of time needed to complete this work.”

Some 40 personnel also are available amid the shutdown on an on-call basis to help process permits authorizing seismic tests to search for oil in the Atlantic Ocean and develop a new five-year plan for selling drilling rights in U.S. coastal waters from mid-2019 through mid-2024.

The bureau says the activity is “critical” to hold the lease auctions on schedule. “Failure to hold these sales would have a negative impact to the Treasury and negatively impact investment in the U.S. offshore Gulf of Mexico.”

“Where did this magical new carryover money come from?” asked Elizabeth Klein, deputy director of the State Energy and Environmental Impact Center at New York University School of Law. “Apparently, they don’t have enough carryover to bring back employees to answer the public’s questions about their day-to-day business or address FOIA requests, but they have enough carryover to push forward a new and unnecessary five-year plan to replace the current one that goes through 2022.”

The recall of furloughed Interior Department workers comes as the agency processes drilling permits and takes other steps to ensure the shutdown does not halt oil and gas development on federal lands and waters.

The Trump administration is using some available funds to push forward a “fossil fuel-oriented energy dominance agenda” in inexcusable ways, said David Hayes, a former deputy Interior secretary.

By contrast, under Obama, Hayes said Interior officials “recognized that the availability of relatively small amounts of these special funding streams for use during a shutdown could create an awkward situation in which it appears that the department may be favoring the provision of some types of services over others.”