The charge was filed with the National Labor Relations Board on June 19. It comes amid a joint campaign of the USW and the International Brotherhood of Electrical Workers to organize the facility.
The joint campaign would involve about 300 production and maintenance employees at the western New York facility.
“Tesla greatly values our employees at our Buffalo facility, and respects their right to organize,” a Tesla spokesperson said in a statement. “The ULP allegation is without merit and we will be responding as part of the NLRB process.”
A USW representative declined to comment on the charge. A copy of the signed charge wasn’t immediately available.
The allegations come six months after Tesla announced a series of layoffs affecting 3,000 employees. Tesla said it saved $43.5 million of costs in the first quarter of 2019 due to the terminations as well as closing some stores.
The Buffalo facility opened in 2017 and has created about 800 jobs since then, according to the company website. The factory produces Tesla’s solar panels, solar roof, Power Wall battery systems, and electrical components for its Supercharger.
The solar production plant stands on a former 88-acre steel manufacturing site.