On leave granted, plaintiff appeals from the decision and order of the Michigan Employment Relations Commission (hereinafter MERC) which affirmed an administrative law judge’s dismissal of plaintiffs petition for an election in order to determine the collective bargaining representative for the Michigan State University Department of Public Safety, Supervisory Division. As amended, the petition included only those employees who attained the rank of lieutenant and captain, presently represented by the intervening defendant which represents all non*544academic supervisory and administrative personnel employed by Michigan State University.
On the record of this case, MERC found "that it would not be appropriate to sever the public safety supervisors from the existing unit of supervisory employees and thereby create a separate supervisory unit”. This finding was based on the following facts and findings:
1. Intervenor’s unit includes approximately 750 employees. Plaintiffs proposed unit would include about 7 persons.
2. There was a community of interest among all units of supervisory personnel, and the community of interest of the proposed unit as police personnel was not unique and distinct.
3. A bargaining history for the intervenor, which included the proposed unit, had existed for several years.
The statute, MCLA 423.28; MSA 17.454(30) vests MERC with broad discretionary authority in its determination of what constitutes an appropriate bargaining unit. The Supreme Court said in Hotel Olds v State Labor Mediation Board, 333 Mich 382, 387; 53 NW2d 302 (1952):
"In designating bargaining units as appropriate, a primary objective of the commission is to constitute the largest unit which, in the circumstances of the particular case, is most compatible with the effectuation of the purposes of the law and to include in a single unit all common interests.”
In Hospital Employees' Division of Local 79, Service Employees' International Union, AFL-CIO v Flint Osteopathic Hospital, 390 Mich 635, 638; 212 NW2d 897 (1973), the Supreme Court said:
"The appellate courts of this state will hesitate to *545substitute a judicial judgment of the appropriate unit for MERC’s determination, and will do so reluctantly and only upon a clear showing of error.”
Our standard of review is set forth in Const 1963, art 6, § 28. The decision of MERC is supported by competent, material and substantial evidence and there is no showing of error.
Affirmed but without costs, a public question being involved.