Tesla workers in New York said on Tuesday they will launch a campaign to form a union, setting stage for the latest labor challenge for chief executive Elon Musk. In a letter to Tesla management, the employees announced their plan to unionize with the Workers United Upstate New York. The union, if formed, would be the first for Tesla, which up until now has managed to avoid unionization at its US facilities, unlike some other major automakers. Musk has in the past been vocal about his opposition to unions and faced the ire of the US National Labor Relations Board when they directed him to delete a 2018 tweet saying employees would lose their stock options if they formed a union. “We believe unionizing will give us a voice in our workplace that we feel has been ignored to this point,” the workers said in a press release on Tuesday. “We are only asking for a seat in the car that we helped build.” The letter, first reported by Bloomberg News earlier in the day, cited employees asking Tesla to respect their right to organize a union and called on the world’s most valuable automaker to sign the Fair Election Principles. Employees said the right to organize a union is a fundamental civil right and the principles would prevent Tesla from threatening or retaliating against workers for organizing a union. Tesla did not immediately respond to a Reuters request for comment.