The National Labor Relations Board has filed a complaint against Apple, alleging that the company “discriminated against employees” at its World Trade Center store, according to Kayla Blado, a spokesperson for the regulator. The NLRB’s investigation was spurred by charges filed in May by the Communications Workers of America, the union working with organizers at Apple retail stores in New York, Atlanta, and Oklahoma. The later store is preparing to hold a vote later this month on whether to become the second US location to unionize.

According to Blado, the NLRB’s complaint alleges that Apple wouldn’t let workers put union fliers on a breakroom table, even though it allowed other solicitations and notices there. She also told The Verge that the agency “found merit” to complaints that Apple had been “interrogating its employees about their support for the union,” and about concerted activities around pay discussions. The full complaint isn’t publicly available yet.

Unless Apple settles with the union, it’ll have to attend a hearing with an NLRB Administrative Law Judge on December 13th. According to Blado, the agency’s regional director wants to make the company post notices informing the workers of their rights (similar to what Amazon had to do last year), and provide training for supervisors. The NLRB can’t charge financial penalties.

Apple didn’t immediately reply to The Verge’s request for comment on the complaint.

In May, the CWA also filed charges claiming that Apple was violating labor laws by holding captive audience meetings in Atlanta, forcing employees to listen to anti-union talking points. Later that month, the union called off an election at the store, saying that Apple’s intimidation of workers and labor violations “made a free and fair election impossible.”