No ordinance granting, amending or renewing a franchise shall be adopted by the commission until a public written report containing recommendations thereon shall have been made to the commission by, or under the direction of, the city manager; until adequate public hearings shall have been held on such ordinance by the commission as a whole, or a committee thereof; and until at least one week after its publication in final form in the manner required for the publication of other ordinances following their passage.