Any city of the second class which has voted to issue bonds for the purpose of constructing or constructing and equipping a hospital or an addition to its hospital and which is unable to proceed with such construction and equipping because of increased costs since the authorization of such bonds may issue additional bonds of the city in an amount not to exceed 50% of the original amount authorized. Before the issuance of any such bonds, the governing body of the city shall cause to be published once each week for two consecutive weeks in the official city paper a notice of its intention to issue such additional bonds. Unless there is filed in the office of the city clerk within 30 days after the first publication of the notice a petition protesting the issuance of such bonds in accordance with this section, the governing body may proceed to issue and sell such bonds.

If within 30 days after the first publication of the notice, petitions signed by qualified electors equal in number to not less than 25% of the qualified electors of the city who voted for mayor at the last city election are filed with the city clerk, the governing body shall submit the question of issuing such additional bonds at the next regular election held within six months after the filing of such petitions, or at a special election called for that purpose if no regular election will be held within that time. If the majority of those voting on such proposition vote in favor of issuing the bonds, the governing body of the city shall proceed to issue and sell the bonds in accordance with the provisions of the general bond law, and none of the debt limitations provided by law shall apply to bonds issued under this act. The proceeds from the sale of such bonds shall be used together with the amount previously authorized for the purposes for which such original bonds were issued.