No ordinance or franchise passed by the council, except when otherwise required by the general laws of the state or by the provisions of this act, except an ordinance for the immediate preservation of the public peace, health or safety, which shall contain a statement of its urgency, shall go into effect before ten days from the time of its final passage, and not then unless within two days after passage, Sundays and holidays excepted, the same shall have been published in full in some newspaper published and generally circulated in said city.  And if during ten days a petition signed by electors of the city, equal in number to at least twenty per centum of the entire vote cast for all candidates for mayor at the last preceding general municipal election at which a mayor was elected, protesting against the passage of such ordinance, or franchise, be presented to the council, the said ordinance or franchise shall thereupon be suspended from going into operation, and it shall be the duty of the council to reconsider such ordinance, or franchise, and if the same is not entirely repealed, the council shall submit the ordinance, or franchise, as is provided by Sub-section (b) of Section Thirty-seven of this act, to the vote of the electors of the city, either at the general election or at a special municipal election to be called for that purpose, and such ordinance or franchise shall not go into effect or become operative unless a majority of the qualified electors voting on the same shall vote in favor thereof.  Said petition shall be in all respects in accordance with the provision of said Section Thirty-seven, except as to the percentage of signers, and be examined and certified to by the clerk in all respects as therein provided.