If the council shall fail to pass an ordinance proposed by the initiative petition, or shall pass it in a form different than set forth in the petition thereof, or if the council fails to repeal a referred ordinance, the proposed or referred ordinance shall be submitted to the electors not less than thirty days nor more than sixty days from the date the council takes its final vote thereon. The council may, in its discretion, and if no regular election is to be held within such period shall, provide for a special election if provided by state law.