The provisions of this act shall not apply to any city, unless and until the question of the adoption of the provisions of this act by such city shall have been submitted to the qualified electors of the city at any regular city election for their approval or rejection and a majority of those voting on the question vote in favor of the adoption of the provisions of this act. The governing body of the city may submit the question of the adoption of the provisions of this act to the electors of such city at any such election, notice of which shall be given by publication in the official city paper once each week for two consecutive weeks, with the last publication not less than five days prior to such election. Such notice shall contain a copy of the proposition to be voted upon.