IN HER FIRST MOVE to exert political muscle following her landslide victory, Boston Mayor Michelle Wu is throwing her support behind Boston City Councilor Lydia Edwards, who is competing in a special election primary for state Senate that will take place in less than four weeks.

Wu was slated to appear on Thursday afternoon with Edwards in East Boston to announce her endorsement in the First Suffolk and Middlesex Senate race.

Boston mayors have long used their powerful perch to back candidates in other races, but the endorsement marks an unusually fast pivot into the political arena for Wu, who was only elected 16 days ago.   

“In this critical moment for Boston and the region, we need unprecedented leadership and collaboration to tackle our biggest challenges. Lydia Edwards is a fearless advocate and community-builder, who has delivered time and again on the changes our families need,” Wu said in a statement released by Edwards’s campaign. 

Edwards, a district city councilor representing East Boston, the North End, and Charlestown, was an early supporter of Wu’s mayoral campaign. She was reelected earlier this month to a third term, but was unopposed and had already announced her run for state Senate. 

Edwards is vying in the December 14 Democratic primary against Revere School Committee member Anthony D’Ambrosio. With no Republicans on the ballot, the Democratic primary winner is all but certain to win the seat in the January 11 general election. 

The seat was vacated earlier this year by Joe Boncore, who resigned to take a job as head of the state’s biotech industry trade organization. 

Edwards, an attorney who championed the cause of immigrants and domestic workers in households before winning office in 2017, is a vivid example of the changing face of Boston politics. A progressive African American, she won a seat held by a succession of Italian-American officials ever since the district council seats were established in 1983. 

Edwards vied for the state Senate seat in her first run for political office, in 2016, when another mid-term vacancy prompted a special election. She placed third in a seven-candidate Democratic primary won by Boncore of Winthrop. 

The district includes all of Winthrop, Revere, and East Boston and a chunk of downtown Boston neighborhoods along with seven precincts in Cambridge.

In recent Democratic primaries, the Boston precincts have accounted for nearly half of the votes in the Senate district. 

Edwards has already racked up a big list of prominent endorsements, including backing from Attorney General Maura Healey, state Rep. Aaron Michelewitz of the North End and state Rep. Adrian Madaro of East Boston. 

The endorsement from Wu only two weeks after her own election gives Edwards a high-profile boost from the Boston mayor who has drawn widespread coverage for her barrier-breaking win as the the first woman and first person of color to be elected to lead the city. 

In her statement, Wu praised Edwards’s work with low-income residents and workers. 

“She’s been the leading voice for housing affordability and workers’ rights, and she’s shepherded through climate justice legislation that reshaped Boston,” Wu said of Edwards. “I need a partner in the State Senate fighting for our shared values and vision of a Boston for everyone.”

Edwards said she was honored by the endorsement and offered an unusually personal thanks to her former city council colleague. “Mayor Wu is my friend and has served as a guiding light personally and professionally,” she said in a statement. “ She saw me before I saw myself. With grace, kindness, inclusion and fierce intelligence Michelle has shown all of us, especially me, how to listen and lead.”