House Republicans hoping for ammunition in their feud with Manhattan DA Alvin Bragg were left empty-handed Friday by a former prosecutor who slammed their probe of Donald Trump’s indictment as “political theater” meant to rile up the former president’s supporters.

GOP lawmakers subpoenaed Mark Pomerantz on the heels of Trump’s indictment last month on 34 felony counts of falsifying business records related to hush money payments to porn star Stormy Daniels before the 2016 presidential election.

Pomerantz, a longtime white-collar crime prosecutor who headed the Trump probe under former Manhattan DA Cy Vance, had been highly critical of Bragg’s handling of the case, and wrote a book about it after he resigned in early 2022.

But in a scathing opening statement, Pomerantz said he would refuse to participate in “cynical histrionics” or answer any questions from the committee led by staunch Trump ally Ohio Rep. Jim Jordan concerning the DA’s office, his book, or anything he’s said about the investigation publicly.

“This deposition is for show. I do not believe for a moment that I am here to assist a genuine effort to enact legislation or conduct legislative ‘oversight,’” reads Pomerantz’s statement, which his attorneys shared with the Daily News.

“We are gathered here because Donald Trump’s supporters would like to use these proceedings to attempt to obstruct and undermine the criminal case pending against him, and to harass, intimidate, and discredit anyone who investigates or charges him.”

Bragg’s office sued the judiciary committee in federal court when it subpoenaed Pomerantz, with a judge ruling the GOP committee was legally entitled to force him to testify. The DA reached a compromise with the Republicans, allowing a lawyer for his office to be present for the sit-down.

Pomerantz quit the Trump probe in February 2022 when Bragg, in office less than two months, disagreed with him that the time was ripe to indict Trump, according to Pomerantz’s book and public comments.

The former prosecutor noted that the law required him to be there or risk contempt — but it also required him to stay silent to avoid harming an active criminal case that has not yet made it before a jury or violating grand jury secrecy.

“Although I have written and spoken publicly about the Trump investigation, I did so before any criminal charges were brought against Mr. Trump,” Pomerantz said.

“Now that a grand jury has indicted him, the circumstances have changed. With formal charges now pending, the rule of law is best served if the merits of the case against Mr. Trump are litigated before the court that is hearing that case.”

Pomerantz noted he was not required to answer questions that could expose him to criminal liability — as Bragg’s office warned he would be for writing the book.

His tell-all memoir, ”People vs. Donald Trump: An Inside Account,” divulged internal debates at the DA’s office about how to charge Trump and Bragg’s misgivings about the case’s now-star witness Michael Cohen.

A spokesperson for Jordan did not immediately respond to a request seeking comment.