(a) Any municipality, in addition to such powers as it has under the provisions of the general statutes or any special act, shall have the power to (1) adopt and amend a charter which shall be its organic law and shall supersede any existing charter, including amendments thereto, and all special acts inconsistent with such charter or amendments, which charter or amended charter may include the provisions of any special act concerning the municipality but which shall not otherwise be inconsistent with the Constitution or general statutes, provided nothing in this section shall be construed to provide that any special act relative to any municipality is repealed solely because such special act is not included in the charter or amended charter; (2) amend a home rule ordinance which has been adopted prior to October 1, 1982, which revised home rule ordinance shall not be inconsistent with the Constitution or the general statutes; and (3) repeal any such home rule ordinance by adopting a charter, provided the rights or benefits granted to any individual under any municipal retirement or pension system shall not be diminished or eliminated.

(b) Any action pursuant to subsection (a) of this section shall be initiated by a resolution adopted by a two-thirds vote of the entire membership of the appointing authority of such municipality, or by petition filed with the clerk of such municipality for submission to the appointing authority and signed by not less than ten per cent of the electors of such municipality, as determined by its last-completed registry list; provided, in the case of a consolidated town and city having a town clerk and a city clerk, such petition shall be filed with the city clerk.

(c) No signature on any petition filed pursuant to subsection (b) of this section shall be valid unless it has been obtained within ninety days of the filing of the page of the petition on which it appears. Any elector signing such a petition may cause his signature to be removed at any time prior to the filing of such petition with the clerk. The clerk with whom the petition is filed shall proceed forthwith to determine its sufficiency by comparing the signatures thereon with those contained in said registry list and shall certify its sufficiency or insufficiency to the appointing authority.

(d) After a resolution has been so adopted by the appointing authority or a petition has been so certified as sufficient, as the case may be, the appointing authority shall not adopt any resolution initiating such action and the clerk shall not accept any petition for the initiation of such action until such time as the commission appointed pursuant to such original resolution or petition has been terminated.