has kept up practices to prevent workers from organizing a union, even as it battles with a U.S. labor agency over allegations that its management violated federal labor laws, a new complaint alleges.

In a complaint filed Dec. 5 with the National Labor Relations Board, the worker—whose name has been redacted under law—claims that Tesla, within the past six months, has “with, restrained, and coerced its employees in the exercise of rights” protected under federal labor laws “by maintaining work rules that prevent or discourage employees from forming, joining, or supporting a labor organization.”

The worker also claims that Tesla has maintained rules that prohibit employees from discussing wages, work hours, “or other terms of condition of employment.”

The unfair labor practice complaint was released on Thursday by the NLRB, in response to a Freedom of Information Act request by Jalopnik. The NLRB redacted the worker’s name, citing exemptions under federal law.

The worker is based at a Tesla warehouse in Lathrop, California, where 500 people are employed, according to the complaint.

A Tesla spokesperson disputedthe claims in an email to Jalopnik.

“Tesla believes the ULP allegations are entirely without merit,” the spokesperson said

The automaker has battled with the NLRB, a government agency tasked with enforcing U.S. labor laws, all year over claims that Tesla management——actively tried to prevent workers from organizing a union.

The NLRB filed a separate complaint against Tesla earlier this year, following up on several claims levied by the UAW, which has been actively trying to organize Tesla’s Fremont, California, factory for two years.

In its complaint, the NLRB alleged that Tesla maintained a confidentiality policy that infringed on workers’ rights, retaliated against workers who supported the union, and restricted employees’ legally-protected union activities in the workplace. Tesla has vehemently denied all the allegations, and Musk in the past that he wouldn’t stand in the way of workers voting on whether they want to be in the union.

It’s unclear what impact, if any, the new unfair labor practice complaint could have on the NLRB’s case, said Harvey Shaiken, a professor at the University of California Berkeley who specializes in labor issues. But Shaiken said the timing of the latest complaint is notable.

“The fact that you have another case while the first is pending creates a bit of a climate of problems that workers are having trying to exercise their right to join a union,” Shaiken told Jalopnik by phone.

“Tesla has been very dismissive of any complaints or any other criticisms of their employment practices, whether it’s related to health care, or accidents, or firing or penalizing workers for wanting to join a union,” he added. “They simply dismiss this as the UAW having a very negative attitude toward the company. But these complaints, particularly when they go as far as the NLRB need to be taken seriously.”

The NLRB if Tesla loses its case, but the automaker could be required to notify workers that it promises not to violate federal labor laws again.

Both the NLRB and Tesla are due to file post-trial briefs to administrative law judge Amita Tracy by Dec. 21. Tracy would then issue a decision thereafter.