By Daniel Wiessner

A federal judge has declined to block a U.S. Department of Labor rule that requires more detailed financial reporting from labor unions, which say the regulation is designed to drown them in paperwork.

U.S. District Judge James Boasberg in Washington, D.C., said on Tuesday that the AFL-CIO, the country's largest labor federation, had not shown that the rule would cause unions irreparable harm, rejecting its bid to stop the rule from taking effect on Wednesday pending the outcome of the legal challenge.

Boasberg, in a brief order, said he would issue a more detailed ruling later this week.

The AFL-CIO and the Labor Department did not immediately respond to requests for comment.

The rule, finalized on June 1 by the department's Office of Labor-Management Standards, will introduce new, longer versions of the financial disclosure forms that unions have been required to submit for decades. The new forms compel more detailed itemizing, including information about officer compensation and travel expenses, and for the first time will separately track foreign transactions.

The department said in adopting the rule that it would modernize reporting requirements to reflect that unions have become larger and more financially complex. The department also said the rule would curb corruption, specifically citing a recent scandal that ensnared two former presidents of the United Auto Workers union.

The AFL-CIO sued earlier this month, claiming the rule was designed to burden unions and drain them of resources needed to organize, advocate for members and engage in collective bargaining. It alleges that the rule violates the federal Administrative Procedure Act.

Boasberg on Tuesday said that any cost to unions of complying with the rule can be recovered later on and does not amount to irreparable harm that can justify a preliminary injunction.

During Trump's first term, the Labor Department adopted a rule expanding reporting requirements for unions to include information about trusts in which they have an interest, including strike funds and real estate trusts. The agency rescinded that rule in 2021 under Democratic former President Joe Biden.

The case is AFL-CIO v. Sonderling, U.S. District Court for the District of Columbia, No. 1:26-cv-02061.

For the plaintiffs: Maneesh Sharma and Matthew Ginsburg of AFL-CIO; Adam Bellotti and others from Bredhoff & Kaiser

For DOL: Dimitar Georgiev-Remmel and Samantha-Josephine Baker of the U.S. Department of Justice