SAN FRANCISCO: The US National Labor Relations Board (NLRB) has filed a complaint against SpaceX, saying it illegally fired eight employees for criticising its CEO Elon Musk.

The labour agency also alleged that SpaceX interrogated, surveilled and threatened workers.

The NLRB will now seek to reach a settlement with SpaceX and if it fails, the aerospace company will face a court hearing in March.

The labour agency claimed SpaceX “created an impression of surveillance” by reading and showing screenshots of messages between employees.

Last year, a group of SpaceX employees wrote an open letter to express concerns about how Musk’s behaviour “is a frequent source of distraction and embarrassment”.

“Elon’s behaviour in the public sphere is a frequent source of distraction and embarrassment for us, particularly in recent weeks. It is critical to make clear to our teams and to our potential talent pool that his messaging does not reflect our work, our mission, or our values,” the open letter read.

At the time, a Business Insider report claimed that SpaceX paid a $250,000 settlement to a flight attendant that Musk sexually harassed.

The letter said that as SpaceX employees, “we are expected to challenge established processes, rapidly innovate to solve complex problems as a team, and use failures as learning opportunities”.

“But for all our technical achievements, SpaceX fails to apply these principles to the promotion of diversity, equity, and inclusion with equal priority across the company, resulting in a workplace culture that remains firmly rooted in the status quo,” the letter alleged.

The NLRB is now asking SpaceX to post a notice about employee rights for 120 days and write letters of apology to employees it fired.