FALMOUTH, Maine — A group of 16 residents is suing the town over a Town Council decision in March to outsource the assessing department to Cumberland County.

Town Manager Nathan Poore said Monday the town was served in late April, and the town’s attorney has filed a motion to dismiss the suit. The town is waiting for a response from the plaintiff and for a judge to rule on its motion.

Poore wouldn’t discuss details of the case, other than to say the town is “very comfortable in its decision.”

The plaintiffs, who claim the council violated the town charter by “abolishing” the assessing department, are represented by attorney John Berry, a Falmouth resident, former candidate for Town Council, and a critic of the plan to outsource. The plaintiffs include former Town Councilor David Libby and Board of Zoning Appeals Chairman Willie Audet.

Berry said he served the town with a summons and a copy of a preliminary petition, a document that seeks authorization from Cumberland County Superior Court to sue the town. He said he is obligated to respond in writing to the town’s motion to dismiss the suit by the end of this week, which he intends to do.

“We simply have to repeat our argument,” he said. “We feel fairly strongly in our position.”

The ultimate objective of the lawsuit is to send the issue to voters on a referendum ballot, Berry said. The suit alleges that the Town Council violated the charter but adds that the charter can be revised by voters, if it is their will.

Two weeks after its 5-2 decision on March 24, the Town Council met in executive session April 10 to discuss the change at the request of Councilor Russ Anderson. Anderson voted against outsourcing because he believed dissolving the assessing department was a violation of the charter and left the town vulnerable to a lawsuit, an opinion he reiterated in a letter published by The Forecaster.

After that meeting, council Chairwoman Teresa Pierce said the decision to outsource would stand because town attorney William Plouffe reaffirmed his opinion that the council had acted within its authority.

The question of outsourcing has become a campaign issue in this year’s Town Council election. Candidates Erin Mancini and Charlie McBrady have both questioned the decision to outsource, while Caleb Hemphill and incumbent Councilor Chris Orestis have said they support the decision.

Regardless of the decision, Falmouth would have needed a new assessor by the end of the fiscal year because longtime assessor Anne Gregory plans to retire on June 31. The town was faced with a choice: hire a new full-time assessor to replace Gregory, or join with Cumberland and Yarmouth in outsourcing that responsibility to the county.

Poore has said consolidation will net the town annual savings between $50,000 and $60,000.