Citizens of Cambridge and several neighboring towns will vote in a special election this spring to fill imprisoned ex-senator Anthony D. Galluccio’s vacant seat in the Massachusetts state legislature, Senate President Therese Murray announced Wednesday.

Galluccio was sentenced to a year in jail after violating his probation for a hit-and-run accident by failing a series of breathalyzer tests. After Galluccio resigned his seat last Tuesday, Senate rules gave Murray 14 days to determine whether to hold a special election.

A primary election will be held on April 13, and a general election on May 11.

“We have an important budget coming up this year as we continue to deal with this recession," Murray said, in an explanation for her decision. "The Senate and the constituents from that district deserve to be fully represented before we begin Senate budget deliberations."

Several contenders have announced their intention to run for the seat, and others are considering a campaign.

Timothy R. Flaherty—who competed against Galluccio for the Senate seat in 2007—has announced that he will run again.

“I’m prepared to run a very vigorous and spirited campaign,” he told The Crimson last week.

Daniel C. Hill, a lawyer from Charlestown, has also declared his intention to run. On Tuesday, Chelsea real estate broker Michael Albano told the Boston Herald that he planned to formally announce his candidacy on Thursday, and the Boston Globe has named Sal DiDomenico, Galluccio’s chief of staff, as a potential candidate.

Marjorie C. Decker, who is currently serving her sixth term as a Cambridge City Councillor, told The Crimson, “I am strongly considering this and there’s a strong chance I’m going to run."

“She would be a major long shot,” Robert Winters, who maintains the political commentary website the Cambridge Civic Journal, said last week about Decker’s possible candidacy. “I don’t think she’s well known outside this district at all."

Winters said he thought that the decision to fill the seat by special election rather than leaving it vacant until the fall would benefit Flaherty, who has run for the seat before and garnered name recognition throughout the Middlesex, Suffolk, and Essex district—which includes parts of Cambridge, Boston, Chelsea, Everett, Revere, Saugus, and Somerville. The Boston Globe endorsed Flaherty in 2007.

“A lot of people who like Anthony Galluccio didn’t mind Tim Flaherty," Winters said. "A lot of that support might carry over."

Galluccio—a Cambridge City Councillor for 14 years who once served as the city’s youngest mayor since 1940—is now serving time in the Middlesex House of Correction. He was elected to the Senate seat in a 2007 special election after Jarrett T. Barrios resigned to run a healthcare company.

Paul R. Nowicki, who came in second in the 2007 race, told The Crimson last week that he would not seek the seat again.

—Staff writer Julie M. Zauzmer can be reached at jzauzmer@college.harvard.edu.