The union representing United States Customs and Border Protection officers has filed a lawsuit against President Donald Trump and his administration claiming they're being forced to work without pay.

The suit filed by CBP Officer Albert Vieira on behalf of the National Treasury Employees Union (NTEU) alleges that the government’s failure to pay wages earned between December 22, 2018, and January 5, 2019, is a violation of the Fair Labor Standards Act (FLSA). Vieira says he and other employees in similar positions should be paid what they’re owed.

The suit is seeking payment of the owed wages, an equal amount of liquidated damages, and other appropriate remedies, according to the lawsuit.

Vieira is regularly posted in Oakland but he’s been working at San Diego's border ports in Otay Mesa and San Ysidro since November.

“These folks have really been kicked into the middle of a political fight they didn’t create and they don’t have the authority to resolve,” Tony Reardon, head of the National Treasury Employees Union, told MSNBC Monday.

Reardon represents roughly 150,000 employees, including Customs and Border Protection officers like Vieira, working without pay during the government shutdown.

Reardon spoke about an e-mail he read from one of his members.

Tuesday night President Trump used a primetime Oval Office address to push for funding for a border wall. A day later the president called a meeting with Democrat leaders on the same issue a waste of time after they rejected his demand for $5 billion in funding for the wall.

The debate over funding triggered the partial government shutdown that is now heading towards its third week.

The National Treasury Employees Union and other federal employee unions are holding a rally Thursday in Washington D.C. Their objective is to put pressure on President Trump to end the shutdown and pay their employees.

Vieira declined to comment on the lawsuit.