The AFL-CIO has filed a complaint with the United Nations over a new federal labor ruling that could block millions of American workers from joining a union or being protected by the nation’s labor laws. The Republican-controlled National Labor Relations Board recently broadened its definition of who can be considered a supervisor to include workers with incidental oversight over coworkers. Under federal law, employees defined as supervisors aren’t entitled to legal protections ensuring their right to join unions. The AFL-CIO filed its complaint with the International Labor Organization of the United Nations. Meanwhile Human Rights Watch has also criticized the labor board’s decision saying it puts the United States in violation of its labor and human rights obligations under international law. The group said the ruling creates a new category of employees — people without the authority of real supervisors and without the rights of ordinary employees.