Groton City Mayor Dennis L. Popp has decided not to seek re-election in May after heading city government for almost 12 years.

“It’s the hardest decision I’ve ever had to make, I think,” he said. “There comes a time in everyone’s life to kind of step aside and let somebody else do it.”

Popp, a Democrat, informed his department heads of his decision Friday and then emailed city councilors. He said he wanted to give parties enough notice to find candidates for the full-time, paid mayor’s office.

Popp said he has no current aspirations for employment or other political office, but he hopes he can “continue to make somebody’s life better.”

As the mayor of the city, a subdivision of the Town of Groton, Popp has at times clashed with town government and more recently, the city fire department’s union.

“That’s me doing what I believe is right for citizens of the city… People have their own opinions,” he said, adding that it wasn’t a factor in his decision.

He believes he will leave the city financially sound, providing services to residents without raising taxes

“I have been blessed,” he said. “I really feel that way.”

At least one city councilor, Deputy Mayor Marian Galbraith, said she would be interested in running for the seat, although it was too soon to elaborate on her plans.

“We may be a small group but a pretty cohesive little city,” she said, praising Popp’s ability to respond to the needs of the community, from saving the Sub Base to the anniversary of Groton Heights.

“We’re a city who steps out on those things and that’s because of Dennis,” she said.