The electors of the City shall have power to propose any ordinance or resolution, except an ordinance for the appropriation of money or an ordinance making a tax levy, and to adopt or reject the same at the polls, such power being known as the initiative. An initiated ordinance or resolution may be submitted to the Clerk of the Council by petition signed by at least five per cent (5%) of the registered electors of the City. When so submitted, the Clerk shall forthwith determine the sufficiency of the petition and if found sufficient, the Council shall at once have the proposed ordinance or resolution read and referred to an appropriate committee which may be a committee of the whole. Provisions shall be made for public hearings on the proposed ordinance or resolution not later than thirty (30) days after the date on which such ordinance or resolution was submitted to the Clerk. The Council shall within forty (40) days after such ordinance or resolution is submitted, take final action thereon, either enacting or rejecting the proposed ordinance or resolution. If the Council fails or refuses to pass such proposed ordinance or resolution or passes it in some form different from that set forth in the petition therefor, the committee of the petitioners may require that it be submitted to a vote of the electors either in its original form or in the amended form by filing with the Clerk a supplemental petition signed by that number of additional registered electors which, when taken together with those who signed the original petition, will total at least ten per cent (10%) of the registered electors of the City, and if said supplemental petition is signed by that number of additional registered electors which, when taken together with those who signed the original petition, will total at least twenty per cent (20%) of the registered electors the date of the election may be fixed therein, not less than sixty (60) days from the time of filing such supplemental petition. Such supplemental petition shall be filed within ten (10) days after the final action on such ordinance or resolution by the Council. The Council shall thereupon provide for submitting such ordinance or resolution to the vote of the electors at the date so fixed, or at the next general election in any year occurring more than sixty (60) days from the filing of such supplemental petition, if no date be so fixed therein.