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.

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.

Shortly after announcing a union campaign at the BlueOval SK Battery Park in Glendale, workers have filed for an election to join the UAW.

A supermajority of workers at an electric vehicle battery campus in Hardin County has filed a petition with the National Labor Relations Board, asking for a union election. Employees of BlueOval SK have formally requested to vote on joining the United Auto Workers.

The BlueOval SK plant, owned by a partnership of South Korea's SK On and Ford, is the latest battery battleground for the union.

The United Auto Workers union is petitioning the National Labor Relations Board to hold an election at a Kentucky battery plant run by a Ford Motor joint venture, the union said in a release Wednesday.

Workers at a Kentucky BlueOval SK Battery Park filed for an election to join the United Auto Workers union Tuesday, marking the new year’s first major union election petition filed in the South —and one that could foretell future union activity in Tennessee.