Favoritism and unfair treatment within the bargaining unit by management and group leaders

Management are using bargaining unit associates "group leaders" to do non-bargaining unit work " supervisor work", and creating an
hostile, and unhealthy work environment. Management at the Trenton facility allow, and encourage this type of behavior. The union has reached out to management on several occasions trying to correct these actions, but management feels it has the right under the " management rights clause". The union  demand all 16 classifications be removed from the bargaining unit, and put under salaried employees.