The third party that the labor union members and LKS Inc. would need is a mediator.
A mediator is someone who helps with resolving conflicts between two group members or more by using certain communication and negotiation skills. A mediator must be a neutral party that are not associated with any of the parties involved in the conflict. In the context of law, mediator is part of fours way of coming to a resolution known as alternative dispute resolution, together with negotiation, collaborative law, and arbitration.