Representatives designated or selected for the purpose of collective bargaining by the majority of the employees in a unit appropriate for such purposes shall be the exclusive representatives of all the employees in such unit for the purposes of collective bargaining in respect to rates of pay, wages, hours of employment, or other conditions of employment, provided, that any individual employee or group of employees shall have the right at any time to present grievances to their employer in person or through representatives of their own choosing.
When a question concerning the representative of employees is raised by an employee, group of employees, labor organization, or employer the commissioner of mediation services or any person designated by the commissioner shall, at the request of any of the parties, investigate such controversy and certify to the parties in writing, the name or names of the representatives that have been designated or selected. The commissioner shall decide in each case whether, in order to insure to employees the full benefit of their right to self-organization and to collective bargaining and otherwise to effectuate the purpose of this chapter, the unit appropriate for the purpose of collective bargaining shall be the employer unit, craft unit, plant unit; provided, that any larger unit may be decided upon with the consent of all employers involved, and provided that when a craft exists, composed of one or more employees then such craft shall constitute a unit appropriate for the purpose of collective bargaining for such employee or employees belonging to such craft and a majority of such employees of such craft may designate a representative for such unit. Two or more units may, by voluntary consent, bargain through the same agent or agents with an employer or employers, their agent or agents. Supervisory employees shall not be considered in the selection of a bargaining agent. In any such investigation, the commissioner may provide for an appropriate hearing, and may take a secret ballot of employees or utilize any other suitable method to ascertain such representatives, but the commissioner shall not certify any labor organization which is dominated, controlled, or maintained by an employer. If the commissioner has certified the representatives as herein provided, the commissioner shall not be required to again consider the matter for a period of one year unless it appears to the commissioner that sufficient reason exists.
In the investigation of any controversy concerning the representative of employees for collective bargaining, the commissioner of mediation services shall have power to issue subpoenas requiring the attendance and testimony of witnesses and the production of evidence which relates directly to any matter involved in any such hearing, and the commissioner or representative may administer oaths and affirmations, and may examine witnesses. Such attendance of witnesses and the production of such evidence may be required from any place in the state at any designated place of hearing, but hearings shall be held in a county where the question has arisen or exists.
In case of contumacy or refusal to obey a subpoena issued under this section, the district court of the county where the proceeding is pending or in which the person guilty of such contumacy or refusal to obey is found or resides shall have jurisdiction to issue to such person an order requiring such person to appear and testify or produce evidence, as the case may require, and any failure to obey such order of the court may be punished by the court as a contempt thereof.