Proceeding pursuant to CPLR article 78 in the nature of mandamus, inter alia, *570to compel the respondent District Attorney of the County of Nassau to respond to a purported motion made pursuant to CPL article 440 to vacate the petitioner’s judgment of conviction rendered January 23, 1990, and, in effect, to compel the Supreme Court, Nassau County, to grant the purported motion. Application by the petitioner to prosecute the proceeding as a poor person.
Ordered that the application to prosecute the 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,
Adjudged that the petition is denied and the proceeding is dismissed, without costs or disbursements.
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 failed to demonstrate a clear legal right to the relief sought.
Further, this Court is without subject matter jurisdiction to entertain the petition insofar as it seeks relief against the District Attorney of the County of Nassau (see CPLR 7804 [b]; 506 [b]). Crane, J.P., Goldstein, Rivera and Lifson, JJ., concur.