Proceeding pursuant to CPLR article 78 in the nature of prohibition, inter alia, to prohibit the respondent Robert Kohm, a Justice of the Supreme Court, Queens County, from conducting a hearing pursuant to Correction Law article 6-C in the matter entitled People v Best pending in that court. Application by the petitioner to prosecute this proceeding as a poor person.
Ordered that the application to prosecute this proceeding as a poor person is granted to the extent that the filing fee imposed by CPLR 8022 (b) is waived, and the application is otherwise denied as academic; and it is further,
*439Adjudged that the petition is denied and the proceeding is dismissed, without costs or disbursements.
“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 here has failed to demonstrate a clear legal right to the relief sought. Mastro, J.P., Lifson, Garni and McCarthy, JJ., concur.