(NewsNation) — A Manhattan grand jury voted to indict former President Donald Trump Thursday in connection to his alleged role in a hush-money payment scheme.

The indictment, which remains under seal, marks the first time a former president is facing criminal charges. Those exact charges are still unknown but will likely be announced in the coming days.

The investigation dates back to 2016 when Trump allegedly directed his former lawyer Michael Cohen to pay off porn star Stormy Daniels who said she had an affair with the former president. Trump has repeatedly denied that claim.

The former president responded to the indictment Thursday evening, calling it “political persecution” and “election interference at the highest level in history” in a statement.

“The Democrats have lied, cheated and stolen in their obsession with trying to ‘Get Trump,’ but now they’ve done the unthinkable — indicting a completely innocent person in an act of blatant Election Interference,” Trump said.

In a statement, Trump’s lawyers said they will “vigorously fight this political prosecution in court.”

Prosecutors said they were working to coordinate Trump’s surrender, which sources told NewsNation would most likely happen Tuesday.

“This evening we contacted Mr. Trump’s attorney to coordinate his surrender to the Manhattan D.A.’s Office for arraignment on a Supreme Court indictment, which remains under seal,” Manhattan District Attorney Alvin Bragg’s office said in a statement. “Guidance will be provided when the arraignment date is selected.”

Cohen previously pleaded guilty to violating federal campaign finance law in connection to the payment after giving Daniels $130,000 through a shell company that he set up.

Trump acknowledged that he paid Cohen a “monthly retainer” as part of an agreement to “stop the false and extortionist accusations” by Daniels, but denied that it had anything to do with campaign funding.

Until now, Trump had avoided charges after federal prosecutors said his company “grossed up” Cohen’s reimbursement for “tax purposes” but ultimately decided against prosecuting the then-sitting president.

In a short statement on Twitter, Daniels’ attorney Clark Brewster said the indictment is “no cause for joy.”

“The hard work and conscientiousness of the Grand Jurors must be respected. Now let truth and justice prevail. No one is above the law,” he said.

In an interview on NewsNation’s “Banfield,” Trump defense attorney Joe Tacopina said “I could care less” what Daniels and her lawyer think about the indictment.

“This case was in the press every day because Michael Cohen, Stormy Daniels, Stormy Daniels’ lawyer, went out there and announced exactly what was happening inside the grand jury,” Tacopina said. “Any normal DA would be mortified by that and understand that the pathological need for media attention is a real problem for the credibility of witnesses.”

Legal experts NewsNation spoke to recently believe the case will be difficult to argue and rely on untested legal theories.

“This is not what the criminal justice system is supposed to be,” prominent attorney and former Harvard Law professor Alan Dershowitz told NewsNation’s Chris Cuomo. “It’s not supposed to be creative, it’s not supposed to bring different statutes together that have never been used against somebody.”

The prosecution’s key witness, Cohen, is a convicted felon and has previously lied to Congress.

Eric Trump, the former president’s son, called the indictment “third world prosecutorial misconduct” and said it’s an “opportunistic targeting of a political opponent in a campaign year.”

Thursday’s indictment marks the conclusion of an investigation the Manhattan District Attorney’s Office has been looking into since 2019.

Bragg, a Democrat, has been criticized by Republicans on Capitol Hill who say the hush money probe is politically motivated.

In a letter last week, House Judiciary Committee Chairman Jim Jordan, R-Ohio, said if Bragg were to prosecute Trump it would “erode confidence in the evenhanded application of justice” and “interfere in the course of the 2024 presidential election.”

Bragg has previously boasted about suing Trump or his administration more than 100 times during his tenure at the New York attorney general’s office.

Thursday’s criminal charges are just one part of the former president’s ongoing legal troubles. Trump also faces criminal probes into his mishandling of classified documents, alleged election interference in Georgia and his role in the events that transpired on January 6.

The Associated Press contributed to this report.