While Attorney General Andrea Campbell has filed suit against Milton, the suit does not include Holden and Millbury.

The state’s highest court has made clear that communities subject to the law must allow for additional, responsible development – and that the law is mandatory, not voluntary,” Attorney

The state’s highest court on Wednesday upheld the controversial MBTA Communities Act as a constitutional law that the attorney general has the power to enforce with legal action, but also ruled that existing guidelines are “unenforceable” because the Healey administration failed to roll them out properly.