A federal employee union and law firm are claiming that it is illegal for the government to require employees to work without pay during a shutdown and plan to take the federal government to court over the issue.

The American Federation of Government Employees and Kalijarvi, Chuzi, Newman and Fitch filed suit against the federal government Dec. 31, 2018, on behalf of those employees being forced to work without pay during the most recent government shutdown.

“Our members put their lives on the line to keep our country safe,” said J. David Cox Sr., AFGE national president, in a news release.

“Requiring them to work without pay is nothing short of inhumane. Positions that are considered ‘essential’ during a government shutdown are some of the most dangerous jobs in the federal government. They are frontline public safety positions, including many in law enforcement, among other critical roles. A substantial number of those working without pay are military veterans. Our nation’s heroes, AFGE members and their families deserve the decency of knowing when their next paycheck is coming and that they will be paid for their work. Our intent is to force the government and the administration to make all federal employees whole.”

The lawsuit is not without precedent.

In 2013, a group of employees represented by the same law firm sued the government over being forced to work during the October shutdown that year. They argued that the Fair Labor Standards Act requires all employees to be paid on time for the work they do, and the U.S. Court of Federal Claims ruled in 2017 that those impacted federal employees were entitled to additional back pay.

“The harm to federal employees began at the first moment of the shutdown. Hundreds of thousands of federal employees are working under sometimes dangerous conditions, including the plaintiffs who were forced to work overtime without pay,” said Heidi Burakiewicz, partner at KCNF DC, in a news release.

“Approximately 420,000 federal employees are continuing to work, but don’t know when they will get their next paychecks. This is not an acceptable way for any employer, let alone the U.S. government, to treat its employees. These employees still need to pay childcare expenses, buy gas and incur other expenses to go to work every day and yet, they are not getting paid. It is a blatant violation of the Fair Labor Standards Act.”

President Donald Trump claimed Christmas Day that federal employees supported the shutdown in order to guarantee funding for a wall at the U.S.-Mexico border, though employees took to Twitter to express their displeasure with the shutdown.

In a recent poll conducted on FederalTimes.com, nearly three quarters of feds said that they do not support the shutdown.

The lawsuit does not apply to federal employees that are furloughed during the shutdown, as they are not performing work without timely paychecks.