Any amendment to any existing charter, whether passed pursuant to the provisions of this act or heretofore granted or passed by the state legislature, for the government of a village, may be submitted to the electors by a 2/3 vote of the legislative body of the village, or may be petitioned for by not less than 20 per centum of the number of electors voting for president at the last preceding election, which petition shall be verified by the oath of the party or parties securing the same and filed with the village clerk. Every such amendment shall be submitted to the electors at the next general or special election. When the amendment originates in the legislative body, it shall be published and remain on the table for 30 days before action is taken thereon. The form in which any proposed amendment to a village charter shall be submitted on the ballot, unless provided for in the initiatory petition, shall be determined by resolution by the legislative body.