No Convention of the People of this State shall ever be called unless by the concurrence of two-thirds of all the members of each house of the General Assembly, and unless the proposition "Convention or No Convention" is first submitted to the qualified voters of the State at the time and in the manner prescribed by the General Assembly. If a majority of the votes cast upon the proposition are in favor of a Convention, it shall assemble on the day prescribed by the General Assembly. The General Assembly shall, in the act submitting the convention proposition, propose limitations upon the authority of the Convention; and if a majority of the votes cast upon the proposition are in favor of a Convention, those limitations shall become binding upon the Convention. Delegates to the Convention shall be elected by the qualified voters at the time and in the manner prescribed in the act of submission. The Convention shall consist of a number of delegates equal to the membership of the House of Representatives of the General Assembly that submits the convention proposition and the delegates shall be apportioned as is the House of Representatives. A Convention shall adopt no ordinance not necessary to the purpose for which the Convention has been called.