Do you believe in coincidences? The Workers United union doesn’t. It claims that Tesla’s decision to fire dozens of workers at its Buffalo, New York, plant is directly linked to the announcement the previous day by some of those workers that they planned to form a union.

Tesla CEO Elon Musk is famously unenthusiastic about unions, and none of his U.S. employees have union representation, unlike workers at Ford, GM and Stellanstis. But earlier this week 25 employees at the Gigafactory 2 site in Buffalo engaged in the development of Tesla’s Autopilot autonomous driving technology revealed they intended to unionize with the assistance of Workers United.

More than 800 analysts are employed at the plant and those in favor of the union plans want pay rises, greater job security and reduced productivity pressures. Bloomberg spoke to workers who claimed Tesla uses software to monitor their keystrokes and track their productivity, putting them under so much pressure that some will skip bathroom breaks.

But the day following the union announcement 30 employees were let go, Bloomberg reporting that at least one of those had been part of a 25-person committee organizing the move towards unionization, and several others who lost their jobs had taken part in labor discussions.

Related: Tesla Opening Chargers To All Electric Vehicles After Deal With US Government

 Tesla Fired Workers After They Announced Plans To Unionize, Employees Claim
Gigafactory 2 employees analyze data to improve Tesla’s Autopilot software

Workers United has filed a complaint with the U.S. National Labor Relations Board accusing Tesla of breaking federal law by terminating the workers “in retaliation for union activity and to discourage union activity.” If Tesla loses the case it may be forced to take back the sacked employees with backpay, but the NLRB can’t make Tesla pay damages to the affected staff.

This is far from the first time Tesla has been in trouble over union matters. In 2019 a California judge found Tesla guilty of engaging in anti-union activity that included allowing security guards to harass employees who were giving out union leaflets, and Elon Musk himself came under fire from a judge who said several of his tweets contained illegal anti-union messages.