State Sen. Nick Collins was left fuming this weekend when he was left off some ballots at a city-run South Boston polling station, as he faces a primary challenge from a candidate backed by his political rival Mayor Michelle Wu.

Collins said “several” residents who went to cast their early voting primary ballot at Condon School on Saturday were provided with ballots listing the wrong state Senate race: the Third Suffolk uncontested race for Sen. Lydia Edwards rather than the First Suffolk race between Collins and Latoya Gayle.

The South Boston Democrat called the error “unconscionable,” and is seeking a review to assess whether the problem extended beyond that one polling place. He said the issue was only caught by the city because three South Boston voters who received ballots without his Senate race noticed it “and fought with the election department.”

“Providing voters with ballots that do not correspond with their districts deprives them of the ability to vote for the candidates they are entitled to vote for and raises serious concerns about voter disenfranchisement,” Collins said Sunday in a statement. “These failures are unconscionable and cannot simply be dismissed, particularly while the City of Boston Elections Department is already under state receivership by the Secretary of the Commonwealth.

“To that end, I am calling for a full review of the entire process to determine the extent of these failures, including whether the same ballot issues may have impacted vote-by-mail ballots that have already been distributed or returned,” Collins added.

The ballot error comes amid Collins’ years-long feud with Wu over his move to block her signature tax shift legislation. Wu is backing Gayle, his Sept. 1 primary opponent.

Collins called for Paul Chong, “the mayor’s hand-picked political appointee with no prior experience managing elections, to step aside and allow election registrar Sabino Piemonte” to “run Boston’s election in partnership with the Secretary of the Commonwealth to prevent any further errors and political interference from the mayor’s office.”

“Boston voters deserve to know they received the correct ballot, that our democratic process is protected, and that their fundamental right to vote has been upheld,” Collins said.

The city on Monday responded to Collins’ allegations by releasing a similar statement to what it provided on Sunday, in response to Collins ally and Boston City Councilor Ed Flynn calling for an independent investigation related to alleged wrong ballots incidents.

Neither city statement mentions that the ballot snafu impacted Collins’ race.

“Ballots have been correctly printed and no candidates’ names were left off the ballot during early voting or vote by mail,” an Election Department spokesperson said on Monday. “On the first day of early voting, the city identified isolated incidents of human error by a poll worker who mistakenly provided the wrong ballot type, but the affected voters were immediately provided the proper ballots for their precinct and voted successfully.

“The city subsequently conducted a ballot inventory and confirmed that the proper number of ballots were cast for each precinct. We encourage all Bostonians to participate in the primary,” the city election spokesperson added.

The incident reportedly took place when a poll worker with a decade of experience at the South Boston polling site misread the precinct number as the ballot label number.

Early voting sites serve a citywide population, meaning poll workers follow protocols to distribute 34 types of ballots in multiple languages available at each location based on voters’ registered voting address.

In-person early voting for the primary kicked off in Boston on Saturday and ends Friday. Any registered voter in Boston can vote early in-person at any of a number of voting sites, including City Hall.

Debra O’Malley, a spokesperson for Secretary of State Bill Galvin’s office, said Monday that means voters at Condon were voting for a number of different race combinations, rather than just those pertaining to South Boston, which led to a poll worker distributing the wrong ballots to three voters.

One impacted voter had arrived alone, and a married couple came together, the city added.

Early in-person voting differs from Election Day, where voters must cast their ballots at their assigned polling place.

“The poll worker handed the voter a ballot for a different precinct,” O’Malley told the Herald. “We looked into it at the time, so our understanding is that there were three voters affected.

“Each one of them received the correct ballot before voting because the voters noticed the issue at the time they were voting, and they went back and got the right ballot. It was a human error by the poll worker who misread the ballot number as the ward number and mixed them up,” O’Malley added.

O’Malley said the Boston Election Department sent people to the early voting site on Saturday to make sure poll workers understood how to provide the correct ballot to voters.

“They also reached out to all the wardens across the city to make sure everybody understood and received a little more training on that, so those mistakes didn’t continue,” O’Malley said. “We asked them to audit the number of ballots at the end of the day, so that they could make sure this wasn’t a more widespread issue.

“Our understanding is that the number of ballots remaining for each ballot style matched what they expected based on who had voted in that location that day,” she added. “As far as we are aware, all of those voters who were affected, it was a total of three, and they were all able to cast the correct ballot.”

She added no incorrect vote-by-mail ballots complaints have been received.

Data from Galvin’s office shows 41% of requested vote-by-mail ballots have been returned in Boston. As of 4 p.m. Monday, 20,775 residents have voted early for a 4.7% turnout.