State Sen. Nick Collins accused the City of Boston of stalling a Council hearing on allegations that it is overtaxing middle-class homeowners to shield Mayor Michelle Wu “from scrutiny” before the primary election.

Collins, a South Boston Democrat who has been feuding with Wu for years over his move to block her signature property tax shift legislation, said the mayor is hiding information from his working-class constituents in the First Suffolk District to benefit his primary opponent, Latoya Gayle.

“City Hall inflated property assessments on working-class homeowners in my district, and the public has a right to know why and how,” Collins said Tuesday in a statement to the Herald. “Middle-class families got hammered by the mayor’s assessing officials while the wealthy got a tax break.”

The City Council had initially scheduled a hearing on the tax assessment discrepancies for June 8, but the hearing was later rescheduled for Sept. 3, two days after the Democratic primary between Collins and Wu-backed Gayle.

Collins said the timing appears to be intentional by City Hall. All three councilors who sponsored the hearing order, Miniard Culpepper, Erin Murphy and Brian Worrell, have endorsed Collins in the Senate race. The hearing was scheduled and is being chaired by Councilor Ben Weber, an ally of the mayor.

“A growing $50 million spending deficit and a $150 million White Stadium boondoggle don’t disappear,” Collins said. “The bill lands on the backs of hardworking taxpayers in my district.

“Now the mayor’s assessing officials are hiding information from the Council and the public until after an election to shield the mayor and her proxies from scrutiny,” Collins added. “My constituents deserve better than smoke and mirrors. It’s past time for the mayor and her assessing officials to face the music.”

Wu fired back Saturday through a spokesperson.

“It hurts all of Boston to have a senator who is nowhere to be found when we need action from the state Senate during legislative session, then pops up in an election year to troll the mayor and city workers,” city spokesperson Marcela Dwork said in a statement.

“This isn’t the first time Senator Collins has made false, insulting accusations about hardworking city workers after blocking tax relief that would have saved Boston homeowners more than $150 million in property taxes by now. Instead, corporate real estate interests received a massive tax break, Senator Collins received a flood of campaign donations from them, and now they are also bankrolling his ads in the Boston Herald, on social media, and in the mail. Boston deserves better,” Dwork added.

Wu’s office said the City Council schedules hearings, not the mayor’s office.

Weber, chair of the Ways and Means committee, said the delay was due to turnover in the Assessing Department. Nicholas Ariniello, the city’s longtime assessing commissioner, announced in late May that he was resigning, which became effective on June 30.

A Council notice states that the June 8 hearing was canceled on June 4.

“We tried a few dates in June but they ended up being used for budget-related matters,” Weber told the Herald Friday. “Eventually, the administration asked for more time to allow the new commissioner to settle in and be able to provide answers to our questions, which made sense to me. We tried a few more dates later in the summer but Sept. 3 was the earliest day that worked for everyone.”

The city appointed Hinlan Wong, a senior leader in the assessing department, as interim commissioner in July while it conducts a search for Ariniello’s permanent replacement.

Weber also said the Council had delayed a vote on the city budget on June 3, and canceled the tax hearing to devote more time to debating the mayor’s budget, ahead of a final vote that was held the following week.

“At no point did the preliminary date factor into this,” Weber said, adding of Collins’ assertions, “I guess I would say that he’s just wrong.”

Collins last month had called for an independent investigation into Boston’s tax assessment practices, as it relates to what he called “the city’s unlawful overvaluation of residential property in Boston’s middle-class neighborhoods.”

His First Suffolk District in the Senate encompasses South Boston and portions of Dorchester, Mattapan and Hyde Park.

Culpepper, a councilor sponsoring the hearing, said when introducing the order last March that he was compelled to look into the matter after seeing that luxury homes in Boston’s most affluent neighborhoods were selling for millions of dollars more than what they were assessed, and therefore taxed, at by the city.

“At the same time,” Culpepper said, “some lower-priced homes appear to be assessed at or even above their sale price, raising concerns about whether the current system is applying valuation practices consistently across different segments of the housing market.”

Culpepper added, “Ensuring that property assessments are accurate and equitable is essential to maintaining public confidence in our tax system and making sure that the responsibility of funding city services is shared fairly across all homeowners.”

Homeowners were hit this year on average with a 13% property tax hike.

Weber said there’s research to suggest that tax assessment discrepancies in Boston are legitimate, but pointed to them as being part of a national trend tied to institutional racism.

“My reading is that there is data suggesting that property sales in historically neighborhoods of color are often below the assessed value,” Weber said, “but I think it has more to do with institutional racism into how the properties are listed and the values that maybe people pay for them.”

Weber said those discrepancies aren’t factored into city assessment practices, which results in a situation where properties are sold and listed below the assessed value — leading to property owners paying higher taxes than what their homes are valued at on the real estate market.

“I don’t know what the solution is,” Weber said, “which is why I think it’s worth having a hearing on it and talking about how we can approach that issue.”

Boston Mayor Michelle Wu blames state Sen. Nick Collins for blocking her property tax bill. Stuart Cahill/Boston Herald