The city’s unions are continuing to split their support among several candidates for the District 3 race.

SEIU Local 888 said this week it’s backing Savin Hill labor lawyer Matt Patton.

Tom McKeever, president of the union that represents city workers, said Patton will be a “strong advocate and partner.”

Boston-area unions are divided, with North Atlantic States Regional Council of Carpenters, IBEW Local 103, Iron Workers Local 7 and Laborers Local 223 supporting John FitzGerald of Adams Village, and members of the Boston Teachers Union and United Auto Workers (UAW) Region 9A supporting Joel Richards of Fields Corner. The Boston Teachers Union has not endorsed anybody in the race, though its members have sent money to Richards.

Meanwhile, Patton also received a boost from his former boss, John Barros, a former city economic development official whose campaign for mayor he ran in 2013.

“From our work together to bring about more affordable housing in our community to ensuring that every child has access to a high-quality education, I know Matt is the best candidate to build a Boston that stands strong for our families and our next generation,” Barros said in an email to supporters.

Patton, who also worked for Gov. Deval Patrick, is getting a boost from Patrick’s former running mate, Tim Murray.

Murray, who before serving as lieutenant governor held the job of Worcester mayor, is hosting a fundraiser for Patton next week. The fundraiser is scheduled for Wed. June 28 at 5 p.m. at the Dubliner restaurant, across from City Hall Plaza.

The preliminary is set for Sept. 12. The other candidates in the race are Meetinghouse Hill civic activist Jennifer Johnson; former schoolteacher and State House aide Barry Lawton of Uphams Corner/Savin Hill; former nonprofit leader Ann M. Walsh of Lower Mills, and housing activist Rosalind Wornum of Ashmont.

CLARIFICATION: This post has been updated to clarify the Boston Teachers Union has not issued a formal endorsement.