Workers at a Ford Motor Co. joint-venture battery plant in Kentucky have formally asked the federal government to hold a vote on joining the United Auto Workers, the union said.

The Kentucky autoworkers, who want to join the United Auto Workers, filed for a union election Tuesday, a key development in the union’s campaign to organize Southern auto-factories and EV battery facilities.

The UAW is trying to rush BlueOval SK into unionization before our full workforce has the opportunity to make a truly free and informed choice,” a company spokesperson said.

The United Automobile Workers union asked a federal labor regulator to conduct an election at a factory Ford jointly owns with a South Korean battery company.