If, before the expiration of 20 calendar days following approval of any ordinance, a petition is filed with the Clerk-Treasurer containing the signatures of not less than 20% of the qualified voters of the town and requesting that the ordinance, or any part thereof, be submitted to a vote of the qualified voters of the town for their approval or disapproval, the Council shall have the ordinance, or the part thereof requested for referendum, submitted to a vote of the qualified voters of the town at the next regular town election, or, in the Council's discretion, at a special election occurring before the next regular election. No ordinance, or the part thereof requested for referendum, shall become effective following the receipt of such petition until and unless approved at the election by a majority of the qualified voters voting on the question. An emergency ordinance, or the part thereof requested for referendum, shall continue in effect for 60 days following receipt of such petition. If the question of approval or disapproval of any emergency ordinance, or any part thereof, has not been submitted to the qualified voters within 60 days following receipt of the petition, then the operation of the ordinance, or the part thereof requested for referendum, shall be suspended until approval by a majority of the qualified voters voting on the question at any election. Any ordinance, or part thereof, disapproved by the voters, shall stand repealed. The provisions of this section shall not apply to any ordinance, or part thereof, passed under the authority of the section of this Charter pertaining to levying property taxes for the payment of indebtedness, adoption of the annual budget, authorizing the annual tax levy, nor to any ordinance or part thereof levying special assessment charges under the provision of this Charter, where the proceeds of such special assessment charges have been or are to be pledged to the payment of any bonds, notes, or other indebtedness incurred or to be incurred by the town for public improvements to be financed in whole or in part by each special assessment charge. The provisions of this section shall be self-executing but the Council may adopt ordinances in furtherance of those provisions and not in conflict with them, and the Council may voluntarily submit to a referendum any ordinance enacted by it, except those specifically excluded hereby.