MEMORANDUM.
The order of the Appellate Division dismissing the prohibition proceeding should be affirmed, with costs.
Just as mandamus will lie only to enforce a clear legal right, prohibition may be availed of only to proscribe a clear legal wrong. That PERB has ordered mediation during the life of the collective bargaining agreement does not, as the City argues, constitute such a clear usurpation of power by PERB, for subdivision 1 of section 209 of the Civil Service Law relates the declaration of impasse "to the end of the fiscal year of the public employer" not to the contract year (see Matter of Burke v Bowen, 40 N.Y.2d 264, 268). Moreover, even as to a clearly ultra vires act, prohibition does not lie against an administrative agency if another avenue of judicial review is available, absent a demonstration of irreparable injury to the applicant if he is relegated to such other course. Here, as the Appellate Division noted ( 97 A.D.2d 258, 262), adequate means exist for presentation by the City of its argument against compulsory arbitration (see 4 N.Y.CRR 205.6). Nor, for like reason, should the authority granted by CPLR 103 to convert this proceeding to an action for declaratory judgment be exercised.
Chief Judge COOKE and Judges JASEN, JONES, WACHTLER, MEYER, SIMONS and KAYE concur.
Order affirmed, with costs, in a memorandum.