One of Connecticut's most popular politicians is stepping down because of a "debilitating" heart condition.

State Comptroller Kevin Lembo is an unapologetic liberal, but even conservatives like him and respect him.

Lembo will step down as state comptroller at the end of this month. He is a major presence in Hartford.

Lembo brought added transparency to state government, and recently he tried, and failed, to launch a public health insurance option.

When former Gov. Dan Malloy opted not to run again four years ago, Lembo explored a run for governor.

Current Gov. Ned Lamont got emotional Friday talking about Lembo's heart condition.

"It breaks my heart. Kevin is a really good friend, an amazing public servant and a young guy with such an amazing future," Lamont said.

Lembo said Friday "Over 10 years ago, voters took a chance on a gay, vegetarian, nerd...It has been the honor of my life to serve the people of Connecticut."

Gov. Lamont will have to replace Lembo.

"Kevin Lembo is one of the most knowledgeable and dedicated policy wonks and leaders I have had the honor to serve with. His fight for transparency and open government has made us all better public servants, and our state government is stronger because of him," said Attorney General William Tong in a statement.

"Kevin Lembo was one of our state's fiercest and most tireless advocates, and I am incredibly saddened to hear of his resignation," said Lt. Governor Susan Bysiewicz. "There was no challenge Kevin wasn't willing to take on. His focus on creating more government transparency has changed the way our state operates for the better."

"Comptroller Lembo has dedicated years to serving our state and its people. He is someone who has always given his all to fight for what he believes in. We share many of the same goals to increase access to health care. Even when we have differed in our approach to a policy, it was always respectful," said Senate Republican Leader Kevin Kelly (R-Stratford) and Senate Republican Leader Pro Tempore Paul Formica (R-East Lyme).

"I'm sorry to learn that Comptroller Lembo is leaving due to health concerns, and I wish him all the best as he steps away from state government to focus on himself and his family," said House Republican Leader Vincent Candelora.