“Many people have asked me over the past two days whether I would consider running for Mayor of Boston. While I thank them for their encouraging words, I want to be clear: I am not interested in running for Mayor. I am not interested in serving as Mayor. I will not be a candidate for Mayor. I am running for the United States Senate," he said in a statement.

Menino announced Thursday he's ending his 20-year tenure at the end of his current term, opening up what will be a contentious fight and the city's first mayoral race without an incumbent in three decades.

While a handful of candidates are already jockeying for the position, including at least six city councilors and three state lawmakers, according to the Boston Herald, Lynch will continue to pursue the seat vacated by Secretary of State John KerryJohn Forbes KerryKentucky candidate takes heat for tweeting he'd like to use congressman for target practice Breitbart editor: Biden's son inked deal with Chinese government days after vice president’s trip State lawmakers pushing for carbon taxes aimed at the poor MORE (D) earlier this year.

Lynch remains the underdog in his pursuit of the Democratic nomination for Senate against Rep. Edward MarkeyEdward (Ed) John MarkeyToyota halts self-driving car tests on public roads Senate Commerce presses Facebook, Cambridge Analytica for answers on data Cambridge Analytica: Five things to watch MORE (D-Mass.), and his name recognition and blue-collar credentials, as well as his Boston background, could have made him a formidable contender in the mayoral race.

But on Thursday, he indicated he'll see the Senate race through to the upcoming primary, on April 30.