The rocket and satellite maker SpaceX has been accused by a US labor agency of unlawfully firing eight employees for circulating a letter calling the founder and CEO, Elon Musk, a ‘distraction and embarrassment’. A regional official with the National Labor Relations Board (NLRB) issued a complaint claiming SpaceX violated the workers’ rights under federal labor law to band together and advocate for better working conditions.

The letter, sent to SpaceX executives in June 2022, focused on a series of tweets Musk had made since 2020, many of which were sexually suggestive. The employees claimed Musk’s statements did not align with the company’s policies on diversity and workplace misconduct and called on SpaceX to condemn them.

The complaint also accuses SpaceX of interrogating employees about the letter, disparaging the workers who were involved, and threatening to fire workers who engaged in similar activity. SpaceX and lawyers for the workers did not immediately respond to requests for comment.

The NLRB’s general counsel acts like a prosecutor and brings cases to the five-member board appointed by the president. If SpaceX does not settle, the case will be heard by an administrative judge, whose decision can be appealed to the board and then to a federal appeals court. A hearing is scheduled for 5 March, according to Kayla Blado, a spokesperson for the agency.

If the NLRB finds that firings violated labor law, it can order that workers be reinstated and given back pay. If SpaceX is found to have violated the law, it could also face steeper penalties in future cases before the board.