BOSTON (AP) -- Boston's longest-serving mayor, Thomas Menino, won't seek re-election for a sixth term amid ongoing health problems.
A person with direct knowledge of his decision told The Associated Press on Wednesday that Menino planned to announce he wouldn't be seeking re-election in November. The person spoke on condition of anonymity because the person was not authorized to speak publicly.
Menino's spokeswoman would say only that the mayor planned an announcement for Thursday. The announcement is expected to be made at an afternoon event at Boston's historic Faneuil Hall.
The 70-year-old Democrat was re-elected to a fifth four-year term in 2009. He has recently faced a series of health problems but has remained popular with voters.
Menino was hospitalized for eight weeks in the fall after a respiratory infection and a blood clot that was complicated by a spinal fracture and diabetes.
He told reporters in November that he had no plans to retire but deflected questions about whether he would seek another term.
Menino's decision is expected to trigger a political scramble to replace him as a new generation of political figures eye the mayor's office.
City Councilor John Connolly announced his mayoral intentions last month, regardless of Menino's decision. But Menino had been considered a heavy favorite had he opted to run.
As recently as January, Menino delivered an upbeat assessment of the city during his annual state of the city address.
Menino used a cane to walk to the podium and spoke vigorously about his plans for Boston. At the time, Menino gave no indication on whether he'd decided to seek a sixth term this year.
"Our progress is real. Our future is bright. The state of our city is striking, sound and strong," he said in prepared remarks that cited progress on economic development and crime reduction.
On Tuesday, Menino appeared at a rally at Boston City Hall plaza to urge the U.S. Supreme Court to repeal the federal Defense of Marriage Act. The previous day, he delivered a speech to the Boston Municipal Research Bureau in which he said he had never been more confident about the city and announced several new development projects and initiatives.
Menino became acting mayor after his predecessor, Raymond Flynn, left office in 1993 after being named ambassador to the Vatican. Menino, then president of the City Council, was automatically elevated to the mayor's job.
The circumstances prompted some critics to label him the "accidental mayor," a charge the sometimes-thin-skinned Menino was quick to reject. But he was elected mayor in his own right in November 1993 and won re-election by wide margins in 1997, 2001, 2005 and 2009.
The city's previous longest serving mayor, the late Kevin White, was in office for four terms, from 1968 to 1984.
Menino's longevity also exceeded the legendary Mayor James Michael Curley, who also served four terms, but not consecutively.
Menino built his reputation by focusing on the unglamorous nuts and bolts of running a major metropolitan city -- fixing potholes, cleaning streets, even curbing the practice of saving a shoveled-out parking space by putting folding chairs or trash cans along the curb.
It's everyday commitments like those that earned him the nickname of the "Urban Mechanic."
The 2004 Democratic National Convention put Menino's political and negotiating skills to the test when the city's main police union threatened to picket over an unresolved contract.
It was only with the last minute help of other politicians, including Republican Gov. Mitt Romney, that a contract was reached in the early morning hours the day before the convention opened.
During his years in office, Menino also became a vigorous national voice in favor of stricter gun control measures.
He co-founded Mayors Against Illegal Guns with New York Mayor Michael Bloomberg and criticized the National Rifle Association's call for more armed guards at schools after the Connecticut school shooting in December.
"That is crazy," Menino said. "Every victim of gun violence and their families knows that's crazy."
Menino also built a reputation for creating an impressive political machine that handily defeated challengers.
Last year, Menino also played a crucial role in helping elect U.S. Sen. Elizabeth Warren, campaigning with her at stops across the city.
Associated Press writer Bob Salsberg contributed to this report.
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