Massachusetts Attorney General Andrea Joy Campbell took nine towns to court Thursday, launching the first enforcement action under a contentious state housing law aimed at unlocking space for multifamily development near public transit. The Mass 9 Towns housing lawsuit, filed in Suffolk County Superior Court, accuses the municipalities of ignoring a state mandate to modernize zoning rules to allow denser housing as of right in at least one area of their communities. Towns Accused of Defying State LawThe defendants — Dracut, East Bridgewater, Halifax, Holden, Marblehead, Middleton, Tewksbury, Wilmington and Winthrop — allegedly failed to revise their zoning bylaws to permit multifamily housing in compliance with the MBTA Communities Act, according to the complaint. A Law Born of a Housing CrunchIn its filing, the attorney general’s office framed the case against the backdrop of a deepening housing shortage. “The commonwealth faces a housing crisis, which is a major cause of the state’s high cost of living,” the complaint states, warning that a limited housing supply has pushed Massachusetts out of reach for many residents — particularly working families, people with disabilities and groups historically shut out of homeownership.