The appeal is dismissed.

The costs of appeal are assessed against the Plaintiff, including the part arising from the supplementary participation.

The grounds of appeal are examined.

1. As to the grounds of appeal Nos. 1, 2, and 3

A. (1) Workers are free to organize a trade union or join it, and a trade union may demand collective bargaining from an employer for its members. On the other hand, the Trade Union and Labor Relations Adjustment Act (hereinafter “Trade Union Act”).

According to Article 29-2(1) of the Trade Union Act, where two or more trade unions exist in a business or workplace regardless of their structural form, each trade union shall, in principle, determine a representative bargaining trade union in accordance with the procedures for simplification of bargaining windows and request an employer to conduct collective bargaining (the main text of Article 29-2(1)). Accordingly, the representative of a representative bargaining trade union shall have the authority to negotiate and conclude a collective agreement with an employer for all the trade unions or union members that have requested bargaining (Article 29(2)). In addition, Article 29-5 of the Trade Union Act provides that, with respect to the scope of the exercise of the power of representation of a representative bargaining trade union among matters that are not directly related to collective bargaining and the conclusion of collective agreements, trade unions shall be deemed a representative bargaining trade union. The introduction of a single bargaining channel for multiple trade unions and the provision that collective bargaining procedures should be unified into a single collective bargaining procedure shall not be effective and effective under Article 55(3), Article 72(3) and subparagraph 3 of the same Act.