A Washington federal judge Thursday promised swift action if the government shuts down again in February, setting an expedited schedule in a dispute where federal employees and labor unions sued over being forced to work without pay for more than a month.

U.S. District Judge Richard Leon suggested the government would face an “uphill battle” against some claims that had been raised in a series of lawsuits that alleged the Trump administration was unlawfully forcing federal employees to report for duty without pay.

Leon raised questions about the Trump administration's recall of 36,000 furloughed Internal Revenue Service workers and whether federal workers could pursue outside opportunities during an appropriations lapse.

Congress and President Donald Trump agreed Jan. 25 to fund the government after the nation's longest shutdown of 35 days. The agreement only funds the government through Feb. 15.

Two unions—the National Treasury Employees Union and the Air Traffic Controllers Association—and a group of five individual federal employees sued in Washington's federal trial court alleging that forced-work without pay violates federal law.

Leon earlier rejected the workers' push to stop the government from requiring employees to report without pay. He said issuing a temporary restraining order would have created “chaos.”

Thursday's hearing was supposed to focus on the workers' request for a preliminary injunction, but Leon converted it to a status hearing after the shutdown ended. He used the hearing to express broad concerns about the possibility of another shutdown. Leon set a hearing for Feb. 22, a pay day that could potentially be missed if the government does shut down in a few weeks.

“If we find ourselves in the unpleasant circumstance, we should act expeditiously,” Leon said. He later added, “I can't imagine a case more important than this one. This involves the shutdown of the United States government.”

Justice Department attorney Daniel Schwei characterized the judge's schedule as speculative, considering there is no certainty the government will shut down again.

Central to the dispute is the Antideficiency Act, the 1870 law that sets the parameters of what happens when agencies run out of federal funding. Generally, federal officials are prohibited from working during a shutdown save for instances that involve the safety of human life or the protection of property.

These “excepted” employees, who are required to work during government shutdowns without pay, argued the government is violating the Fair Labor Standards Act and also provisions of the U.S. Constitution that require due process.

Leon questioned whether the IRS employees being recalled to work to send refund checks should be deemed an essential function. He called this argument an uphill battle for the government.

Paras Shah, assistant counsel for the National Treasury Employees Union, said he was pleased the judge appeared receptive to the union's argument about whether IRS employees should be considered essential during a shutdown. He also said the union would press its case even if the government remains open.

Leon also said Thursday he wanted to be briefed from the Justice Department on what non-government work employees, furloughed or working without pay, are allowed to pursue during the appropriations lapse.

At a previous hearing in the case, Michael Kator of Washington's Kator, Parks, Weiser & Harris, who represents individual federal workers, asked the court to give employees the option to work or stay home to find alternate work until the shutdown is lifted. Kator said the government forced these workers into “involuntary servitude” in violation of the Constitution.

The Justice Department later disputed that workers were not able to work outside of the daily jobs, and could not cite a regulation that did not allow federal workers to take extra work, such as driving for Uber or Lyft.

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