Section 4. Public employers may recognize an employee organization designated by the majority of the employees in an appropriate bargaining unit as the exclusive representative of all the employees in such unit for the purpose of collective bargaining. All notices relative to a representation petition and all elections shall be posted at the request of the commission ten days prior to a hearing in a conspicuous place where the affected employees are employed.

The commission, upon receipt of an employer's petition alleging that one or more employee organizations claims to represent a substantial number of the employees in a bargaining unit, or upon receipt of an employee organization's petition that a substantial number of the employees in a bargaining unit wish to be represented by the petitioner, or upon receipt of a petition filed by or on behalf of a substantial number of the employees in a unit alleging that the exclusive representative therefor no longer represents a majority of the employees therein, shall investigate, and if it has reasonable cause to believe that a substantial question of representation exists, shall provide for an appropriate hearing upon due notice. If, after hearing, the commission finds that there is a controversy concerning the representation of employees, it shall direct an election by secret ballot or shall use any other suitable method to determine whether, or by which employee organization the employees in an appropriate unit desire to be represented, and shall certify any employee organization which received a majority of the votes in such election as the exclusive representative of such employees.

Except for good cause no election shall be directed by the commission in an appropriate bargaining unit within which a valid election has been held in the preceding twelve months, or a valid collective bargaining agreement is in effect. The commission shall by its rules provide an appropriate period prior to the expiration of such agreements when certification or decertification petitions may be filed.

Nothing in this section shall be construed to prohibit a stipulation, in accordance with regulations of the commission, by an employer and an employee organization for the waiving of hearing and the conducting of a consent election by the commission for the purpose of determining a controversy concerning the representation of employees.

Any hearing under this section may be, when so determined by the commission, conducted by a member or agent of the commission. The decisions and determinations of such member or agent shall be final and binding unless, within ten days after notice thereof, any party requests a review by the full commission. If a review is requested, the member or agent shall file with the commission and with the parties a written statement of the case. In addition any party may, within ten days from the receipt of such statement, file a supplementary statement with the commission. A review by the commission shall be made upon such statement of the case by the member or agent and upon such supplementary statements filed by the parties, if any, together with such other evidence as the commission may require.

Notwithstanding any other provision of this section, the commission shall certify and the public employer shall recognize as the exclusive representative for the purpose of collective bargaining of all the employees in the bargaining unit an employee organization which has received a written majority authorization, but this shall apply only when no other employee organization has been and currently is lawfully recognized as the exclusive representative of the employees in the appropriate bargaining unit. Whenever an employee organization proffers evidence that it has received a written majority authorization, the employee organization and the public employer shall agree upon a neutral to conduct a confidential inspection of the evidence of a written majority authorization. If within 10 days the employee organization and the public employer do not agree upon a neutral, the commission shall act as the neutral. The neutral shall verify the employee organization's majority support within the appropriate bargaining unit and report the results of its inspection in writing to the parties and, if the verification was conducted by an agreed neutral, to the commission, which shall in turn certify the results to the parties in writing. The commission shall establish rules and procedures for the prompt verification of evidence of a written majority authorization, which rules shall include safeguards to protect the privacy of individual employee choice, and which shall further provide that, absent exceptional cause, the verification procedure shall not last longer than 30 days after the appointment of the neutral or after the assumption by the commission of the duties of the neutral.