The US Capitol.
Washington CNN  — 

The Senate Judiciary Committee will investigate claims made by former US Attorney Geoffrey Berman in his forthcoming book that Trump-era officials in the Justice Department pressured his office to “aid them politically.”

“Throughout my tenure as U.S. attorney,” Berman writes in the book according to The New York Times, which obtained a copy of it, “Trump’s Justice Department kept demanding that I use my office to aid them politically, and I kept declining – in ways just tactful enough to keep me from being fired.”

Berman, the former US attorney for the Southern District of New York and a Trump appointee, was later fired by the former President.

Judiciary Chair Dick Durbin sent a letter to Attorney General Merrick Garland Monday, saying, “These reported claims indicate astonishing and unacceptable deviations from the Department’s mission to pursue impartial justice, which requires that its prosecutorial decisions be free from political influence.”

“They also compound the already serious concerns raised by then-Attorney General Barr’s 2020 efforts to replace Mr. Berman with a Trump loyalist,” the Illinois Democrat wrote.

“If accurate, Mr. Berman’s claims indicate multiple instances of political interference in the Department’s investigative and prosecutorial decisions,” he wrote. “The Senate Judiciary Committee will investigate these episodes.”

Durbin also requested the Justice Department provide the committee numerous documents and communications by October 3.

Welcoming the committee’s investigation, Berman told MSNBC on Monday night, “I think a light has to be thrown on this kind of outrageous conduct that really corrupted the Department of Justice and turned it into a political instrument for the president.”

He detailed why he wrote the book – “Holding the Line,” which is due out Tuesday – saying that he “wanted people to understand the full scope of the outrageous and improper political interference by Trump’s Justice Department in the cases of the Southern District of New York.”

“It demonstrates what Trump is capable of and what he’s likely to do, and it also provides a frontline view of just how vulnerable our justice system is,” he said.

CNN’s Manu Raju contributed to this report.