Embattled District 6 Councilor Kendra Lara’s vote to support a budget that would have slashed millions from essential city services cost her the endorsement of a union that represents roughly 1,700 city workers.

The Boston Presidents’ Committee of the American Federation of State, County and Municipal Employees, endorsed Lara in the 2021 general election, but opted to back one of her opponents, William King, this time around.

The endorsement, announced by King in a Wednesday campaign email and confirmed by an AFSCME Council 93 representative, comes two months ahead of the Sept. 12 preliminary election, and is somewhat of a rarity in Boston politics, a former city official told the Herald.

“It’s rare that in a three-person contest with an incumbent that they would have endorsed the challenger,” said Larry DiCara, a former City Council president and longtime observer of Boston politics. “The very fact that anybody is endorsing six weeks ahead of the preliminary, that means something is stirring out there.”

King, an information technology specialist, and Benjamin Weber, a workers’ rights attorney, are vying to unseat Lara, who was elected in the fall of 2021. The primary will narrow down the field to two candidates for the November election.

The endorsement comes at an inopportune time for Lara, who is facing charges for crashing an unregistered and uninsured car into a Jamaica Plain home on June 30. She is also charged with driving with a revoked license, and was traveling at twice the speed limit when the crash occurred, according to a Boston Police report.

Mayor Michelle Wu and City Council President Ed Flynn both made critical statements about the incident, but that didn’t factor into the endorsement, according to Christopher “Tiger” Stockbridge, co-chairman of the Boston Presidents’ Committee.

“You can’t hold somebody to the fire for that stuff there,” Stockbridge told the Herald. “Everybody makes mistakes. There’s a higher court than the unions that are going to decide that stuff.”

Lara, 33, is due to appear in the West Roxbury Division of Boston Municipal Court for a clerk magistrate’s hearing on July 19.

Rather, the decision was based on how Lara voted in the fiscal year 2024 budget process, Stockbridge said.

“The mayor came out with a budget that funded our jobs fully,” he said. “The Council decided to vote against the budget, not once but twice. That voted against securing the jobs for the AFSCME employees and the funding for them. We don’t support that.”

Endorsements have not been officially announced, but the union also opted to back, or not back, other incumbents, based on how they voted on the budget, Stockbridge said.

The Council had voted for a budget with amendments that would have slashed millions from the police, transportation, public works, library and veterans departments, among others. It was ultimately vetoed by Wu, effectively eliminating the cuts.

Lara told the Herald on Friday that she “has appreciated and continues to appreciate the support of AFSCME, both two years ago when I ran for office and during my tenure as a city councilor.”

“They have to go through their endorsement process and make decisions about what candidates to support, and I will be, and continue to be a champion for their workers, with or without their endorsement,” Lara said.

Lara also said she stands by her budget vote.

“I think as elected officials, we have to take difficult votes that sometimes don’t make everybody happy,” she said. “I took a difficult vote and I’m going to continue to do my work.”

King reached out and asked for the endorsement, Stockbridge said.

“We were extremely happy and grateful to get their support, King said. “It’s a big win for the campaign.”

Citing the pending charges against the councilor, King, a 33-year-old West Roxbury resident, said he is running because “the district deserves better” than its current representation. District councilors should be “role models,” he said, and this incident demonstrated “poor judgment” on Lara’s part.

Weber declined to comment much on the matter, saying that he was “focused on finding ways for the Council to better serve people in the district.”

When asked about her re-election chances, Lara said she has “a lot of work to do” in the weeks leading up to the preliminary.

“My hope during this election season is that my constituents are able to weigh my mistake against the work I’ve done for them the last two years,” she said.

A resident also filed a complaint with the Boston Election Department on Thursday, “formally challenging” Lara’s residency in the district she represents.

A department official said Friday a review is underway with the city’s legal team to determine whether the challenge has merit, and should be considered by the Boston Election Commission.

Lara disputed rumors that she was living outside of Boston, telling the Herald Thursday that she lives at 46 Saint Rose St. in Jamaica Plain, the address listed on her campaign filing with the city’s Election Department.

Lara would have likely “done quite well” in her re-election bid, “were it not for the troubles,” DiCara said. Now she has two opponents, one of whom may have access to “Liss-Riordan kind of money,” he speculated, referring to Weber.

Weber works for Lichten & Liss-Riordan, which describes itself as a nationally recognized law firm founded by high-profile labor attorney Shannon Liss-Riordan, who ran unsuccessfully for state attorney general in 2022 and U.S. Senate in 2020.

Weber filed his campaign organization statement with the Office of Campaign & Political Finance on July 5, and has only made one deposit, for $2,500, which was filed on Wednesday.

Lara, a progressive-leaning councilor who previously worked as director of radical philanthropy at Boston-based Resist, has just $7,025 in the bank. King has $2,701 cash on hand, OCPF reports show.

With a low turnout, driven by a lack of an at-large race due to the withdrawal of longtime Councilor Michael Flaherty, expected in the September preliminary, any incumbent, including Lara, is “vulnerable,” DiCara said.

In 2019, a year that lacked a mayoral election, but included a citywide council race, turnout for the preliminary was just 11.17%.

The endorsement to watch, DiCara said, is that of the Jamaica Plain, or JP, Progressives, which backed Lara two years ago. Failing to receive that one would mean Lara, who lives in Jamaica Plain, is losing her base, he said.

Weber, 49, a self-described progressive who lives in Jamaica Plain, said he plans to seek the endorsement of JPP, “as well as a broad coalition of organizations from every corner of my district.”

Lara said she is actively seeking the JPP endorsement, and plans to participate in a candidates’ forum the group has scheduled in August.

Weber also plans to participate, but King said he may decline. He passed on the first forum held before Weber joined the race, due to the bias he thought JPP was showing toward Lara. He cited the group’s social media activity and campaign donations from members of its steering committee.

“I just didn’t feel like we were going to get a fair shot,” King said.