Massachusetts Constitution Amendments Art. XLVIII, Init., Pt. III, § 2

The general court may, by resolution passed by yea and nay vote, either by the two houses separately, or in the case of a constitutional amendment by a majority of those voting thereon in joint session in each of two years as hereinafter provided, submit to the people a substitute for any measure introduced by initiative petition, such substitute to be designated on the ballot as the legislative substitute for such an initiative measure and to be grouped with it as an alternative therefor.