A union of administrative law judges on Monday sued over the constitutionality of President Donald Trump's appointees to a federal labor panel, arguing the members should have been approved by the Senate, and therefore, their rulings should be thrown out.

In a complaint filed by Gupta Wessler attorneys, including Deepak Gupta, the Association of Administrative Law Judges allege the 10 current members of the Federal Service Impasses Panel—a group of presidential appointees that can resolve gridlocked labor disputes between a federal agency and its employees—should not have been allowed to issue a ruling last week that implemented the union's new contract.

"Despite this serious constitutional defect, the panel is wielding substantial government power: It is asserting jurisdiction over federal labor unions, issuing final orders that are purportedly binding on those unions, and imposing long-term contract provisions on the unions against their will—including restrictions that go even further than those requested by employers," reads the complaint, filed in the U.S. District Court for the District of Columbia.

"And the panel's unconstitutional exercise of these broad governmental powers is more egregious still because, unlike most federal agencies, its actions are unchecked—the merits of the panel's actions generally are not subject to any further administrative or judicial review," the Gupta Wessler lawyers argue.

The administrative law judges, who typically oversee Social Security disability hearings, claim parts of their new contract with the Social Security Administration should be nullified due to the unconstitutionality of the appointees, who set the terms of those disputed parts of the contract. The union argues the panel is stacked with anti-labor figures, who sided with the administration on most disputes and, in some instances, placed even tougher restrictions on the judges than those proposed by the administration.

For example, the Gupta Wessler attorneys wrote, the Social Security Administration had wanted to cap the amount of time judges could spend on union representation efforts to 2,000 hours a year, compared to the unspecified "reasonable amount of time" proposed by the judges. But the panel capped that time to 1,200 hours annually in the contract.

"Given that the association's yearly official-time usage for the past 19 years has ranged between 19,000 and 22,000 hours, the panel's decision renders the association incapable of meaningfully representing its members or performing its statutory duties," the lawsuit reads. "It would reduce the staff that the association would have to represent its members or perform its statutory duties from 10 full-time equivalents to one-half of a full-time equivalent."

Representatives for the union and the Social Security Administration were able to successfully negotiate most of the contract, but were unable to reach an agreement for some components. That's when the administration took the matter to the impasse panel, whose rulings are binding and unreviewable, according to the complaint.

The complaint says the union questioned whether the panel had jurisdiction to handle the deadlocked negotiations between the administration and the judges, but the panel stated in its final decision "that it 'considered and rejected all of the union's objections prior to asserting jurisdiction over this matter,' including the argument that 'the panel's composition violates the appointments clause of the United States Constitution,'" without providing any reasoning for doing so.

"Here, the panel has purported to assert the power to issue decisions binding on one of those federal-sector unions: the Association of Administrative Law Judges. Because the panel lacks authority to do so, the association brings this constitutional challenge," the lawsuit reads. "The association asks this court to issue a declaration that the panel is unconstitutionally composed and that its actions are null and void and an injunction to prevent any of the panel's unconstitutional actions from taking effect."

This is not the first challenge filed over the board's current appointees: Just last month, the American Federation of Government Employees' National Veterans Affairs Council sued in D.C. district court, making similar constitutional claims.