Eight SpaceX employees said they were sacked for the part they played in an open letter criticising Elon Musk.
The former employees, who were fired in June, have filed unfair labour practice charges with the National Labor Relations Board.
According to the New York Times, the letter criticised Musk’s online behaviour while employees also asked the company “to publicly address and condemn Elon’s harmful Twitter behaviour."
After the letter was written it is believed 20 employees met with a top SpaceX executive where they were told that they were distracting the company and that the letter was an “extremist act.”
Nine of the 20 employees were subsequently fired, with eight of them bringing further charges against Musk, who has been making headlines for weeks over his actions at Twitter.
Earlier today, it was revealed that Twitter employees were locked out of office buildings for at least the weekend amid reports more staff are leaving the company, either by choice or being sacked.
There were reports that many staff decided to quit after Musk, who bought the company for US$44bn, called on employees to sign up for “long hours at high intensity” or leave.
Following mass sackings by Musk, and resignations from employees who were unhappy with the regime, some departing staff are suggesting that this could be the end of Twitter.
Musk and Tesla, the company where he is CEO, have had a previous run-in with the National Labor Relations Board.
In 2021, it upheld a decision that found Tesla engaged in unfair labour practices for firing a worker who attempting to unionise and for Musk discouraging unionisation through his tweets.