Whenever the Congress of the United States proposes an amendment to the Constitution of the United States and proposes that the same shall be valid when ratified by conventions in three fourths of the several States, the Governor of this State shall fix by proclamation the date of an election for the purpose of electing delegates to such convention of this State. Such election may be either at a special election or may be held at the same time as a general election or special, but shall be held at least as soon as the next general election occurring more than 3 months after the amendment has been proposed by the Congress.