Federal labor officials accused the rocket company SpaceX on Wednesday of illegally firing eight employees for circulating a letter critical of the company’s founder and chief executive, Elon Musk.

According to a complaint issued by a regional office of the National Labor Relations Board, the company fired the employees in 2022 for calling on SpaceX to distance itself from social media comments by Mr. Musk, including one in which he mocked sexual harassment accusations against him.

The letter circulated by the employees also called on SpaceX, which has more than 13,000 employees, to clarify its harassment policies and enforce them consistently.

The labor board complaint said the company’s president and chief operating officer, Gwynne Shotwell, had illegally restricted employees from circulating the letter, and it identified similar infractions by other executives and managers.

The case is scheduled to go before an administrative judge in early March unless SpaceX agrees to a settlement beforehand. A spokeswoman for the labor board said it was seeking make-whole remedies like reinstatement and back pay for the workers.

“At SpaceX the rockets may be reusable, but the people who build them are treated as expendable,” said Paige Holland-Thielen, one of the employees who were fired. “I am hopeful these charges will hold SpaceX and its leadership accountable for their long history of mistreating workers and stifling discourse.”