(1) Negotiations between the employer and the exclusive bargaining representative of a unit of uniformed personnel shall be commenced at least five months prior to the submission of the budget to the legislature. If no agreement has been reached sixty days after the commencement of such negotiations then, at any time thereafter, either party may declare that an impasse exists and may submit the dispute to the commission for mediation, with or without the concurrence of the other party. The commission shall appoint a mediator, who shall promptly meet with the representatives of the parties, either jointly or separately, and shall take such other steps as he or she may deem appropriate in order to persuade the parties to resolve their differences and effect an agreement. A mediator, however, does not have a power of compulsion. The mediator may consider only matters that are subject to bargaining under this chapter.

(2) If an agreement has not been reached following a reasonable period of negotiations and mediation, and the executive director, upon the recommendation of the assigned mediator, finds that the parties remain at impasse, then the executive director shall certify the issues for interest arbitration. The issues for determination by the arbitration panel shall be limited to the issues certified by the executive director.