LOWER MANHATTAN (PIX11) — Supporters of former President Donald Trump are set to rally in Lower Manhattan on Monday in protest of the ongoing grand jury testimony that Trump has claimed will lead to his arrest.

The demonstration, set to begin at 6 p.m., is organized and described by the New York Young Republican Club as a “peaceful protest” of what it characterizes as Manhattan District Attorney “Alvin Bragg’s heinous attack on President Donald J. Trump and the legitimacy of the American judicial system.”

The gathering, which is billed as only being open to members of the club plus the Long Island Loud Majority conservative group, comes on the eve of the day on which Trump has said he expects to be arrested. 

In a Saturday social media post, Trump claimed that he “WILL BE ARRESTED ON TUESDAY” in the case, which concerns hush money paid to women who, during his 2016 campaign, alleged past sexual encounters with Trump. In the same message, Trump called on supporters to “PROTEST, TAKE OUR NATION BACK!” 

The NYPD on Monday was positioning extra barricades in Lower Manhattan in preparation for a possible indictment of the former president.

The preparations came as Robert Costello, an attorney allied with Trump, was expected to testify Monday before the grand jury, the Associated Press reported, citing a person familiar with the situation who was granted anonymity to discuss the secret proceedings.

In addition to working with fellow Trump allies Steve Bannon and Rudy Giuliani, Costello also briefly served as a legal adviser to Michael Cohen, a key witness in the investigation. Cohen previously pleaded guilty in connection to the hush money payments to adult film star Stormy Daniels and model Karen McDougal, which he alleges were directed by Trump.

Trump, who is running for a second White House term in 2024, has denied having sex with either woman, and has characterized Cohen, a former longtime lawyer for the Trump Organization, as a liar. 

Bragg’s office, which has not shared a timeline for the grand jury proceedings, has declined comment on Trump’s claims of imminent arrest.

This article includes reporting from the Associated Press.