The powers and rights of the initiative and referendum are reserved to the people of the municipality as prescribed by law. The assembly, by ordinance, shall regulate the procedure for their exercise but such regulations shall require that a petition to initiate or repeal an action be signed by qualified voters of the municipality equal in number to at least twenty percent of the total number of electors voting at the last regular annual election and the subject of the petition shall be submitted to the voters at the next previously scheduled municipal special or regular election that will be held at least 40 days after certification of the petition. However, a special election must be scheduled not less than 40 days or more than 90 days after filing of a petition containing the signatures of not less than 1/3 of the total number of electors voting at the last regular annual election.
A vote of a majority of the electors who vote on the question shall be required. An ordinance adopted by the initiative procedure may not be amended or repealed by the assembly for a period of one year after the date of the election at which it was adopted, and should two or more ordinances adopted at the same election have conflicting provision, the one receiving the largest affirmative vote shall prevail. Ordinances repealed by referendum shall be null and void from the day following the day of the election.