If an election is to be held not more than three months nor less than thirty days after the publication of such notice by the Clerk, such proposed ordinance shall be submitted to a vote of the electors at such election. If no election is to be held within the time aforesaid, the election officers shall provide for submitting the proposed ordinance to the electors at a special election to be held not later than sixty days nor earlier than thirty days after the publication of such notice, if the petition for such ordinance and the petition for such election so demand, and if the signers of the two petitions amount in the aggregate to at least twenty-five percent of the total number of voters voting at the last regular election of municipal officers, otherwise the same shall be submitted at the next regular or special election. At least ten days before any such election, the Clerk of the Council shall cause such proposed ordinance to be published.