Lynnfield Selectman Al Merritt announced Monday night that he will resign effective December 31 as he continues his battle with what he described as a difficult medical condition.

"Attending to my medical care has become more challenging, and is consuming more of my time and energy," said Merritt, reading from a prepared statement. "Unfortunately, I"m often unable to participate fully in meetings, discussions and planning sessions involving town matters that require selectmen input."

Merritt has served the town of Lynnfield in a variety of ways over the years. He was elected to the board of selectmen in 2008 and was re-elected in 2011 to a three-year term. He also served a couple of terms as a finance committee member in the 1980s and 1990s, and chaired the town's school building committee in 2001 and its economic development and housing advisory committee in 2005. He is also the selectmen's liaison to the committee working on bringing an athletic fields complex to Lynnfield.

Merritt's colleagues strongly praised both his character and his years of service to the town.

"You certainly have exemplified the highest and best of the citizen selectmen, looking for nothing but the best interests of the citizens and the town," said Select Board Chair Bob MacKendrick.

Fellow selectman Dave Nelson recalled how he had first met Merritt during his own time on the finance committee. "I find Al to be a very good person with a deep heart," said Nelson, adding that wherever he goes in town, somebody often ends up mentioning to him that Merritt is a good man.

Town Administrator Bill Gustus added that in light of all of the selectman's contributions to the town's major initiatives in recent years, "this has been the Merritt decade."

"You are the one constant in the entire town that I've been involved with Lynnfield," Gustus told Merritt, adding that the people of Lynnfield had been "extremely lucky" to have him, and predicting that the selectman will continue to be involved with the town.