The U.S. government agency has filed a complaint against the Elon Musk-owned company, alleging SpaceX forced workers to sign illegal confidentiality and non-disparagement agreements as a condition of getting severance pay.

The complaint, which was filed Wednesday evening, further alleges SpaceX required employees to agree to bring any legal disputes with the company to arbitration, rather than court, and were not permitted to participate in class action suits against the company, which the NLRB says is illegal.

SpaceX, the agency said in its filing, has been “interfering with, restraining and coercing its employees in the exercise of [their] rights.”  The complaint looks to force the spaceflight company to rescind the agreements and not enforce them for workers that have already signed them.

SpaceX did not respond to a request for comment by Fortune.

The company has made its feelings about the NLRB clear in the past, however. SpaceX sued the NLRB in early January, arguing the structure of the agency is unconstitutional. Trader Joe’s and Amazon have made similar claims.

The SpaceX lawsuit against the NLRB came one day after the labor agency accused SpaceX of unlawfully firing employees who wrote an open letter critical of Musk and of creating the impression worker activities were being surveilled.

SpaceX has denied those charges.

The case for that complained had hearings earlier this month. It’s expected to be months before a decision is reached and perhaps as long as a year.

If SpaceX doesn’t agree to settle the most recent complaint, the case will go before an administrative law judge at the NLRB in late October.