*887“Because of its extraordinary nature, prohibition is available only where there is a clear legal right, and then only when a court — in cases where judicial authority is challenged — acts or threatens to act either without jurisdiction or in excess of its authorized powers” (Matter of Holtzman v Goldman, 71 NY2d 564, 569 [1988]; see Matter of Rush v Mordue, 68 NY2d 348, 352 [1986]). Similarly, the extraordinary remedy of mandamus will lie only to compel the performance of a ministerial act and only when there exists a clear legal right to the relief sought (see Matter of Legal Aid Socy. of Sullivan County v Scheinman, 53 NY2d 12, 16 [1981]).
The petitioner has failed to demonstrate a clear legal right to the relief sought. Prudenti, PJ., Angiolillo, Florio and Sgroi, JJ., concur.