1. One-third or more of the tenants occupying a dwelling located in the city of New York or the commissioner of the department of the city of New York charged with enforcement of the housing maintenance code of such city, or in the counties of Nassau, Suffolk, Rockland and Westchester may maintain a special proceeding as provided in this article, upon the ground that there exists in such dwellings or in any part thereof a lack of heat or of running water or of light or of electricity or of adequate sewage disposal facilities, or any other condition dangerous to life, health or safety, which has existed for five days, or an infestation by rodents, or any combination of such conditions; or course of conduct by the owner or his agents of harassment, illegal eviction, continued deprivation of services or other acts dangerous to life, health or safety.

2. If the proceeding is instituted by the commissioner of the department of the city of New York charged with enforcement of the housing maintenance code of such city, one-third or more of the tenants may, at any time thereafter during the pendency of the proceeding or after final judgment pursuant to section seven hundred seventy-six or seven hundred seventy-seven of this article, petition for substitution of themselves in place and stead of such commissioner of such department. Such substitution shall be ordered by the court unless good reason to the contrary shall be shown.