A group hoping to bring open primaries to New York City is taking the city clerk and the city's Board of Elections to court after they thwarted the group’s effort to bring the issue to voters.

In court papers filed Tuesday, United NY, a nonpartisan advocacy group focused on election reforms, claims it filed more than enough valid signatures. But the city clerk invalidated the group’s petitions based on a review conducted by the Board of Elections.

The group’s executive director slammed the city, saying it is acting on behalf of partisan interests.

"This is by-the-book establishment politics, and we expected it,” said Anthony Thomas, Unite NY’s executive director. “The Board of Elections’ job is to favor political parties, not the overwhelming number of voters who support open primaries, or the 1.1 million independents shut out of the system.”

The court filing asks that a judge review its petitions line-by-line.

Vincent Ignizio, the deputy executive director and spokesperson of the New York City Board of Elections, declined to comment citing pending litigation. The city clerk did not immediately respond to a request for comment.

Unite NY has proposed asking voters if the city’s closed primary system, which only permits people to vote if they are registered in the party holding a primary, should change so that all registered voters can participate in the June elections. Its proposal would replace a party primary with a nonpartisan preliminary election open to all voters and conducted with ranked-choice voting. The top three finishers would then move on to the general election in November, which would also use ranked-choice voting.

Last month, the group filed petitions with the city clerk following a process set out in the state’s Municipal Home Rule law, which governs how cities amend their charters. That law requires the clerk to send a notice to the City Council within 30 days confirming whether or not the petitions comply with the statutory requirements based on the New York City Board of Elections review of petitions.

Unite NY claims it submitted 42,000 valid signatures and engaged Lawrence Mandelker, an experienced election law attorney, to vet its petitions before they were submitted.

In a letter to City Council Speaker Julie Menin on Tuesday, City Clerk Michael McSweeney wrote that he found the petitions lacked the necessary 30,000 valid signatures required under law. The city said the group only filed 38,000 signatures and disqualified more than 23,000, arguing that the individuals who signed were not registered and eligible to vote in the last general election.

The city said the petitions only contained 14,000 valid signatures.

“The failure to meet this threshold renders the petition invalid,” McSweeney wrote.

Other signatures were invalidated for technical reasons, like, “the failure of signers to insert certain requisite information such as the signer's name or address, the failure to provide a legible signature, and the failure to have such signatures correctly witnessed,” the letter stated.

The city Board of Elections includes 10 commissioners who are picked by the Democratic and Republican Party leaders of each borough. They also routinely conduct nonpartisan special elections when there is a vacant seat between election cycles.

Unite NY had already anticipated that its question would be bumped this election cycle because of Mayor Zohran Mamdani’s charter revision commission, which produced five questions that will be on the ballot in November. Under state law, those questions take priority this year.

However, since Unite NY submitted petitions under the Municipal Home Rule Law, a question that’s bumped because of the mayor’s charter revision commission could still appear on the ballot next year if it otherwise meets the requirements. But in rejecting the petitions, the city said the proposal also did not meet the legal criteria to appear on a future ballot.

The clerk’s letter also states that the city’s Corporation Counsel also found the petitions invalid because the submission failed to include a financial plan for how to pay for the proposed changes, which is required under state law. The city also argues that the proposed amendment, “exceed the City's local legislative authority; and is impermissibly vague and misleading to voters.”

A Gothamist investigation last year found that petitions submitted by previous Mayor Eric Adams re-election campaign in 2025 contained numerous forged signatures. At the time, the Board’s role was to verify enough signatures were submitted, but it did not scrutinize them for authenticity.