Massachusetts’ controversial law aimed at boosting housing near transit is facing a cascade of legal challenges in the wake of State Auditor Diana DiZoglio’s determination that the measure is an “unfunded mandate.”

The auditor’s opinion on the MBTA Communities Act — which requires jurisdictions with transit stops to rezone for more multifamily housing — argues that the law forces communities to boost housing and change infrastructure with no financial support from the state.

Last Friday, Middleborough took the issue to court. The town argued in a filing in Plymouth County Court that it is already in compliance with the MBTA Communities Act after rezoning for more multifamily housing in 2021, and thus should not have to further update its zoning.

“The one-size-fits-all interpretation of the MBTA Communities Act is unreasonable and is not what the Legislature intended,” said Town Manager Jay McGrail. “What we’ve done in Middleborough should be modeled and celebrated, not punished.”

Marshfield and Wrentham both followed suit this week, arguing the towns shouldn’t have to foot the bill for zoning changes. Wrentham Town Manager Michael King said in a statement that town leaders were inspired by the state auditor’s determination.

“The Town had previously exercised its rights to seek a determination from the State Auditor that the MBTA zoning law constitutes an unfunded mandate,” he said. “Ultimately, the Auditor, through its Division of Local Mandates, agreed, declaring that the law constitutes an unfunded mandate and directing the Commonwealth’s housing agency, EOHLC, to provide required information on the fiscal impact of the law including on Town services and infrastructure.”

The suits come despite a January ruling by the Massachusetts Supreme Judicial Court confirming that the MBTA Communities Law is constitutional and valid, and that State Attorney General Andrea Campbell has the power to enforce it.

Campbell said in the wake of DiZoglio’s “unfunded mandate” determination that her office still plans to enforce the measure .

The vast majority of the 177 communities affected by the law are in compliance with the state, having either filed new zoning plans or preliminary action plans.