Manhattan District Attorney Cyrus Vance Jr. in a sternly worded letter to Gov. Andrew Cuomo, accused the state's chief executive of violating the separation of powers Tuesday, when he pulled Vance's authority to investigative allegations of assault and intimidation leveled against former attorney general Eric Schneiderman in favor of Nassau District Attorney Madeline Singas, who the governor appointed as a special prosecutor earlier in the evening,

In a letter to both newly sworn-in acting Attorney General Barbara Underwood and DA Singas, Cuomo announced Singas' appointment as the special prosecutor he promised on Monday after the publication of a New Yorker article detailed allegations of nonconsensual violence against a number of former Schneiderman ex-girlfriends. Schneiderman announced his resignation within hours of the story's publication.

Singas was charged by the governor with investigating allegations that Schneiderman slapped, choked, intimidated and violently threatened a number of ex-girlfriends, as well as the suggestion in the article that AG office staff and resources may have been used to facilitate the allegations detailed in the piece.

While noting that Singas would work with Suffolk County DA Tim Sini, who has jurisdiction over the Hamptons location where some of the allegations were said to have occurred, as well as any other DAs that may have various jurisdictional purview, Cuomo said the Manhattan DA's office would no longer be involved.

Vance's shop had, “at minimum, an appearance of conflict,” Cuomo said, because the Manhattan DA's office was currently being investigated by the attorney general for its handling of allegations of sexual assault against Hollywood producer Harvey Weinstein.

“There can be no suggestion of any possibility of the reality or appearance of any conflict or anything less than a full, complete and unbiased investigation,” Cuomo stated. “The victims deserve nothing less.”

In his Tuesday night letter to Cuomo, Vance said he agreed with the governor's position on the needs of the victims, but argued that any conflict of interest “was one of [Cuomo's] creation.” It was, after all, the governor who ordered then-AG Schneiderman to investigate any improper handling of sexual assault allegations against Weinstein in 2015, Vance said.

The details of a failed police sting against Weinstein and the suggestion by some that Vance's office failed to properly handle the case were the subject of a previous New Yorker article that led to numerous Hollywood actresses coming forward to allege sexual harassment and assault at Weinstein's hands. Vance has defended his office's handling repeatedly, most recently in a scathing article in New York Magazine that suggested rich defendants receive preferential over poor ones by Manhattan prosecutors.

In his letter, Vance said Cuomo's decision in March to have Schneiderman investigate the Manhattan office's actions represented “an unwarranted intrusion by an elected executive into a charging decision by an independent prosecutor.”

Raising the specter of untoward political motivation, Vance noted that, the day Cuomo directed the AG's office to investigate was the same day Cynthia Nixon announced her campaign, which, Vance said, was seen by some as “politically motivated.”

“I have no idea whether or not that is true,” he continued. “But more important, and beyond politics, it violated the separation of powers that is intended to promote confidence in the independence of our criminal justice system.”

Vance argued that the governor “intrud[ing] further into the criminal process” by giving Singas power over any Schneiderman investigation in Manhattan “only compounds the mistake” of Cuomo's decision to have the AG investigate the DA's office in the first place.

For Vance, the fact that there is zero overlap between the Weinstein investigation and any investigation into Schneiderman's actions—“they involve entirely separate claims of assault, involving entirely separate parties”—and that the fact one of the supposedly conflicted parties, Schneiderman, is no longer in a position to be conflicted, there is simply no conflict.

In a revealing note, Vance stated that Cuomo had essentially acknowledged the dissipation of any potential conflict on Monday.

“I pointed this out to you on the telephone last night, and you agreed at that time that Mr. Schneiderman's resignation would obviate any conflict for our office,” Vance stated in the letter.

In the end, Vance argued, independent prosecutors, “answerable to local constituents,” should be left in charge of local charging and jurisdictional issues.

“Interference with law enforcement investigations by an elected chief executive should always be viewed with great care, especially these days, given the propensity of our elected executive at the federal level in Washington to make statements and take actions that jeopardize the independence of our criminal justice system,” the Manhattan DA stated.

In a statement sent late Tuesday, Alfonso Davis, counsel to the governor, called Vance's letter “editorial commentary” that was “both inappropriate and misguided given the ongoing investigations.”

“Confronted with the reality of a conflict, we took action to ensure both the integrity of the investigation and the public's confidence in the process,” Davis said. “In doing so, we put in place an elected official and independent prosecutor who could preside over the investigation without the specter of conflict or compromise.”

In a followup letter sent Wednesday to correct, as Davis put it, “blatant misstatements of facts” by Vance, the governor's counsel argued that the Manhattan prosecutor was wrong to suggest the investigation only concerned “private citizen” Eric Schneiderman.

Davis referred back to the language in Cuomo's letter that called on the special prosecutor to also look into whether staff or office resources were used to further the alleged misconduct by Schneiderman. As the AG's office is still investigating Vance over the Weinstein case, Davis said it was “frankly absurd” to think the Manhattan DA's office could investigate that same office the way the special counsel would.

Davis went on to make clear that the governor's office was still asking the attorney general's office to investigate the relationship between the Manhattan DA and the city's police department in the handling of sex crimes. Davis said Acting AG Underwood had been contacted “to ensure the process begins ASAP.”