A Greene County resident will file suit early Monday morning to challenge the legality of new state Assembly district maps after the state Court of Appeals on Wednesday voided the Legislature's Senate and congressional lines for partisan gerrymandering.

Activist and former Senate candidate Gary Greenberg of New Baltimore will file the challenge in state Supreme Court in Steuben County, as first reported in the New York Daily News.

Greenberg, a Democrat, will be the sole plaintiff in the court challenge after the Democrat-led state Court of Appeals ruled in a 4-3 decision Wednesday that the Congressional and Senate maps adopted by the Legislature were procedurally unconstitutional, the activist said Friday night.

"The Assembly maps were drawn in the same process," Greenberg said. "They didn't follow the directions under what voters wanted and voted to change in the New York constitution. [Senate Deputy Majority Leader] Mike Gianaris and the district assemblyman who edited the maps used the same staff to draw the congressional, Senate and Assembly districts. They drew these maps up wrong," he continued. "They thought since it was Democratic judges, they thought it was a shoe-in, that the appeals process would go their way. Well, it backfired."

Greenberg declined to disclose his chosen counsel until the case is filed next week.

The initial Republican-backed lawsuit to challenge the legislative-drawn lines was filed in Steuben County in February. Petitioners did not file to invalidate the Assembly redistricting maps in their challenge to the state's highest court.

Representatives with Assembly Speaker Carl Heastie's office could not immediately be reached for comment Friday.

Greenberg will file in the same Southern Tier court because the judge is already familiar with the case, he said. Greenberg said no one had contacted him to put him up to the task, and added he was inspired by a New York Daily News editorial published Wednesday stating the Assembly districts would also have been voided if they had been challenged.

"We may not invalidate the Assembly map, despite its procedural infirmity," according to the Court of Appeals' decision Wednesday.

A state Supreme Court judge on Friday ruled to set the Senate and Congressional primaries for Aug. 23. The Assembly primary election remains June 28, unless the Legislature or state Supreme Court take action.

The court should determine all decisions about the primary and petitioning process, said Greenberg, who added signatures should have to be gathered again for the new districts to be drawn by appointed special master Carnegie Melon University Fellow Jonathan Cervas by May 20.

The Legislature and Gov. Kathy Hochul should not be involved, Greenberg said.

"They shouldn't have a second chance to set the rules," he said. "The districts these signatures were obtained in are illegal. They've been ruled unconstitutional. They should have to go back out and get the signatures in the correct, legal districts."

There is less than two months until the Assembly's scheduled primary date. Greenberg does not expect his suit to stall in court in wake of the highest court's ruling Wednesday.

Greenberg campaigned to become the Democratic nominee for the 46th Senate District in 2020. He has not ruled out running for a state seat this year, but said his decision to file the challenge to the Assembly maps is unrelated to a potential political campaign.

"These seats should have been done correctly," Greenberg said. "I'm a voter and I want to make sure this is done correctly. I've always fought for fair and competitive elections. None of them were drawn correctly. [Democrats] have all three bodies of government and all they had to do is follow the constitution and get it right. The Legislature should be kept out of the process as much as they can. They're the ones who caused all this."

Any petition challenging the state's redistricting legislation must be served to the attorney general, Senate president, Assembly speaker and governor. Greenberg spearheaded the movement to pass the Child Victims Act for victims of childhood sexual assault, establishing the Fighting for Children PAC and ProtectNYKids Inc. to lead the effort.