Reviving a dispute that played a role in the recently settled fight between port operators and longshore workers, two groups representing trucking companies now claim a program under which truck trailers used to haul containers are inspected by the dockworkers’ union violates federal law.

Members of the American Trucking Association’s Intermodal Motor Carriers Conference and the Institute of International Container Lessors, which represents container and companies that own and lease the trailers, called chassis, have sent letters to the Federal Maritime Commission asking that it and the Federal Motor Carrier Safety Administration fix the alleged violations and enforce the law on the inspection and maintenance of the chassis.

The trade groups said the new program was agreed upon under the labor contract between the International Longshore and Warehouse Union and the Pacific Maritime Association that was ratified in May.

Because neither the ILWU nor the PMA own or provide the chassis covered by the inspection program, the letters state, dockworkers don’t have the right to inspect or repair the chassis owned by the trade group members under the federal law. In addition, their members are not part of the ILWU and PMA agreement, the letter states.

“These ILWU activities in fact only highlight their long-claimed ‘jurisdiction’ over chassis inspection and repairs and serve to advance their drive to add to and/or protect union jobs,” the letters state. East Coast dockworker labor contracts include similar language, one of the letters said, and similar disruptions may soon occur there.

The groups have asked the commission to fix the alleged violations and work with the FMCSA to enforce the law on the inspection and maintenance of the chassis.

“The inspection program is unnecessary, illegal and is encumbering port and industry efforts to address and mitigate port congestion problems,” said Curtis Whalen, executive director of the intermodal conference.

The ILWU did not return a call for comments in time for publication.