(a) An attorney who is employed as a public officer or employee in any court in this judicial department shall not maintain an office for the private practice of law, alone or with others, hold himself out to be in the private practice of law, or engage in the private practice of law; such attorney shall not participate, directly or indirectly, as attorney or counsel in any action or proceeding, pending before any court or any administrative board, agency, committee or commission of any government, or in the preparation or subscription of briefs, papers, or documents pertaining thereto.

(b) By special permission secured from the presiding justice of this judicial department as to each professional engagement, a person referred to in subdivision (a) of this section may engage in the private practice of law as to matters not pending before a court or governmental agency, in uncontested matters in the Surrogate's Court, uncontested accountings in the Supreme Court, and other ex parte applications not preliminary or incidental to litigated or contested matters. Such approval, which shall continue only to the completion of the particular engagement for which permission was obtained, shall be sought by application in writing to the presiding justice of this judicial department (processed through the immediate supervisor and the administrative judge or other head of the court or agency in which applicant is employed for his comment and recommendation including restrictions, if any), which shall state the position occupied, all pertinent information as to the matter to be handled (including the name of the client engaging such attorney and the prior relationship, if any, between such client and said attorney) and that in the event of litigation the applicant will immediately withdraw as attorney and notify his administrative judge or other head of the court or agency thereof.

(c) A person referred to in subdivision (a) of this section shall not engage in any other practice of law which is incompatible with or would reflect adversely upon the performance of his duties.