JEFFERSON CITY, Mo. — A coalition backed by unions and progressive groups is pushing a Missouri ballot measure that could reshape the way boundaries are drawn for Missouri’s House and Senate districts.

Clean Missouri is planning kickoff events Saturday for its petition drive to get the proposed constitutional amendment on the 2018 ballot.

It would make Missouri one of the first states to mandate the use of a new statistical model for redistricting that is intended diminish partisan gerrymandering.

The measure also would impose gift limits for legislators, lower their campaign contribution limits, make individual lawmakers subject to the Sunshine Law and change how long former lawmakers must wait before they can become lobbyists.

The group received $250,000 this week from the Missouri National Education Association.