Massachusetts Attorney General Maura Healey is pushing back against the latest challenge to the state's requirement that tugboats escort oil barges through Buzzards Bay.
The Cape Cod Times reports Healey's office is asking a federal court for permission to intervene in a lawsuit filed by the industry group American Waterways Operators.
The tugboat rule was part of a state law put in place after a major oil spill in Buzzards Bay in 2003.
In a statement, Healey calls the law a "common-sense" approach and one that since enactment has likely prevented other oil spills from occurring.
Industry groups have challenged the rule unsuccessfully in the past. The latest suit argues federal law should supersede state law.
American Waterways says its personnel can safely navigate the bay without the tugboat escorts.