Update: The lawsuit was dismissed by a Delaware County judge.

A lawyer for two candidates running for Delaware County Council said Friday that a vendor hired by the county sent out hundreds of mail ballots for next Tuesday’s election to the wrong voters.

In a petition filed in county court, the attorney, longtime Republican lawyer Michael Puppio, asked for an emergency hearing to determine the scope of the problem and possible remedies, arguing the mistakes have put “the integrity of the municipal election ... at stake.”

After hearing nearly four hours of testimony Saturday, Common Please Court Judge Kelly Eckel gave both sides until Monday to file briefs.

Delaware County has acknowledged that 670 flawed absentee ballots were mailed to voters on Oct. 25; the mailing addresses did not match the voter information on the ballot inside, causing some people to receive another person’s ballot. If the recipient didn’t catch the mistake, filled out and returned the ballot, they might inadvertently prevent another voter from casting a vote.

The county said it has taken steps to identify those ballots and send new ones to the voters who received them.

But the suit filed by Puppio alleges the vendor, Ohio-based ElectionIQ, “has not been forthcoming ... regarding the extent of their errors,” and seeks further clarity ahead of Tuesday’s election. “If an immediate hearing is not held to determine the extent, if we are able to at this late date ... the validity of the municipal election on November 2, 2021 is in jeopardy,” the lawsuit says.

The suit references the vendor error and also names several people who had problems with their absentee ballots, which are different from mail-in ballots and sent out by the county, not the vendor.

Reached late Friday, Delaware County Director of Elections James P. Allen said the compromised ballots are easy to sequester and examine individually. He said the county was aware of the lawsuit and plans to respond.

“We’re gonna clear up some misunderstandings that are in the lawsuit,” he said.

ElectionIQ, based in Akron, did not immediately respond to requests for comment Friday evening.

According to the petition, Howard Gartland, chairman of the Radnor Township Republican Party, received complaints from voters about incorrect ballots, which he forwarded to the county. In an email Wednesday, the county included a letter that outlined its response.

In it, Allen said voters who realized they received a mismatched ballot should destroy it. Then they can wait for the replacement mailing, visit a voter services center in Media to get a new ballot — which would also cancel out the replacement mailing — or go to their precinct on Election Day and vote with a provisional ballot, the letter said.

“We operate on the need to be 100% successful in our operations, not 99.9,” the letter said. “We truly regret the inconvenience this has caused you.”

Ballots in Delaware County had already been delayed because of an issue with the contractor, according to an Oct. 13 meeting of the election board. Ballots slated to go out in September were not sent out until Oct. 15, prompting some voters to complain about the short turnaround before the election.

The lawsuit names as plaintiffs the Republican candidates for County Council, Frank Agovino and Joseph Lombardo. Puppio said that’s because he knows and works with them and had to put the petition together quickly, but that he expects “all 45,000 voters who requested a mail-in [ballot] and every candidate on the ballot has a standing interest in this.”

Council is the biggest local race in Delaware County on Tuesday. Voters statewide will also vote on Supreme, Superior Court, and municipal judges.

At a time when election integrity has increasingly come under attack — often baselessly — Puppio said his issue is not with Delaware County and he’s not accusing anyone of malfeasance. It’s the vendor he wants to hear from.

“This isn’t a partisan matter,” he said. “I’m not saying that anyone at the Delaware County bureau of elections misled anyone, said anything intentionally incorrect, or that there’s any nefarious behavior going on,” he said.

“What we’re saying in this complaint is ... both parties’ candidates have been out working real hard since February. ... Some of these elections are going to be decided by one or two votes. ... Let’s get a handle on this now. Let’s fix it.”

Staff writer Melanie Burney contributed to this article.