Final answer:
One action a labor union can take if its demands are not met is to go on strike. This involves workers collectively refusing to work to pressure the employer to meet their demands for better working conditions or compensation.
Step-by-step explanation:
Labor unions have played a significant role in shaping work conditions over the years. When their demands are not met by management, one action that unions can take is to go on strike. A strike involves workers collectively refusing to work until their demands, which often include better wages or working conditions, are met.
Organized labor and collective bargaining have been core strategies for unions to exert power and negotiate terms with employers. However, in some cases where negotiations stall or demands are not addressed satisfactorily, a strike can be a last resort to pressure the employer into making concessions. Despite potential legal restrictions, especially for public sector workers, strikes have historically been a potent tool for the labor movement.