Tesla Inc. supervisors at a Florida service center violated U.S. labor law by telling employees not to discuss pay and other working conditions or bring complaints to higher level managers, a U.S. labor board official has ruled.

Managers at the Orlando repair shop illegally silenced workers in 2021 after some of them complained that new hires were being paid more, according to the decision issued Tuesday by National Labor Relations Board (NLRB) Administrative Law Judge Michael Rosas. 

The judge ordered Tesla to cease and desist from violating workers’ rights and to post notice of the violations in the service center and email it to employees. 

The ruling is the latest loss for Tesla before the labor board as it also faces lawsuits alleging widespread race and sex discrimination at its assembly plants. 

Tesla did not immediately respond to a request for comment. 

In late 2021 employees became aware that new hires at the collision center were being paid a higher hourly rate than existing workers, according to the decision. 

Several workers complained, including a technician who contacted a Tesla vice president and had his complaint forwarded to the company’s head of human resources, according to the ruling.

Supervisors at the service center held a meeting where they instructed the facility’s 25 employees not to discuss their pay and other working conditions and not to file complaints with higher level managers, Rosas said. Weeks later, the technician who had complained was fired, according to the decision. 

The technician filed a complaint against Tesla with the NLRB last year, and Tuesday’s ruling came after Rosas held a hearing in February. 

Tesla had argued that it had quickly repudiated the managers’ comments by posting a notice in the service center that Tesla policy allowed workers to discuss their pay. 

The judge said that attempting to silence employees violated their fundamental right under U.S. labor law to band together to advocate for better working conditions. 

The decision came about a month after a U.S. appeals court upheld an NLRB ruling that Tesla CEO Elon Musk broke the law by tweeting that employees would lose stock options if they joined a union. The company is also appealing an NLRB decision that said it unlawfully barred factory workers from wearing union t-shirts. 

The world’s most valuable automaker is also facing a series of race discrimination and sexual harassment lawsuits, most involving its flagship assembly plant in Fremont, California. Tesla has denied wrongdoing in those cases.