Any proposed ordinance may be submitted to the council by petition signed by voters of the city equal in number to the percentage hereafter required. The signatures, verification, authentication, inspection, certification, amendment and submission of such petition shall be the same as provided for petitions under sections 78.260 to 78.290. If the petition accompanying the proposed ordinance be signed by voters equal in number to twenty-five percent of the votes cast for all candidates for mayor at the last preceding election, and contains a request that the said ordinance be submitted to a vote of the people if not passed by the council, such council shall either:
§ 78.200, RSMo