"Since you said you had no intention of resigning, I asked the president to stop you today, and he did," Barr wrote in a letter to the fired Manhattan federal prosecutor, Geoffrey Berman, published by the US media.

Barr accused prosecutor Berman of having "opted for public entertainment over public service."

Since being appointed by a federal court to head the powerful New York Southern District attorney's office in 2018, Geoffrey Berman has overseen the process against former Trump lawyer Michael Cohen.

He also investigated the efforts of former mayor and now presidential adviser Rudy Giuliani to discredit political opponents of the president, and two associates of Giuliani accused of violating the campaign finance law and helping to dirty Trump's opponent, the presidential Democrat Joe Biden, in the Ukraine scandal that led to the impeachment of the president.

Initially, Attorney General William Barr announced Berman's resignation on Friday night, saying Trump would nominate Securities Commission chief Jay Clayton instead, a corporate attorney inexperienced in prosecutions.

"I thank Geoffrey Berman, who is resigning after two and a half years of service as the United States Attorney for the Southern District of New York," Barr said in a statement.

"Our investigations will advance"

But Berman, who is a Republican and a donor to Trump's presidential campaign, said he learned of his apparent departure in Barr's statement.

"I have not resigned and I have no intention of resigning," Berman said in a press release.

"I will resign when the Senate confirms a candidate appointed by the president. Until then, our investigations will proceed without interruption," he said.

Berman also investigates crimes committed by the late financier and suspected child molester Jeffrey Epstein, who was a friend of Trump, and his associates.

"Barr's attempt to overthrow Prosecutor Berman late Friday night, when Berman leads several investigations that are politically sensitive to the president, certainly threatens the rule of law," Peter Shane, a professor of law at the University , told AFP from Ohio and expert on separation of powers.

Democratic Senate leader Chuck Schumer urged the Justice Department inspector general to investigate the reasons behind the government's efforts to get Berman out of office.

Jay Clayton "can either let him be used in the brazen Trump-Barr plan to interfere with prosecutorial investigations for the Southern District of New York, or he can face this corruption, withdraw his name from consideration, and save his own reputation for ruin overnight, "Schumer said on his Twitter account.

Jerry Nadler, Democratic head of the House of Representatives judicial committee, accused Barr of repeatedly interfering "in criminal investigations on behalf of Trump."

"We have a hearing on the issue on Wednesday," Nadler tweeted. "We welcome Berman's testimony, and we will invite him to testify," he announced.

Why?

"Barr needs to be clear about why he wanted Berman out, and more importantly, ensure that the underlying investigations will not be affected by this change in leadership," Jonathan Turley, a professor of constitutional law at George Washington University , told AFP .

For Turley, the announcement late Friday night "was itself a serious mistake that only magnifies concerns about the political motivations of the action."

In recent months, the Trump administration has fired or demoted Inspectors General of the Pentagon, the State Department, the intelligence community and the Department of Public Health.

Geoffrey Berman's predecessor in office, Preet Bharara, was fired in 2017 after refusing to resign from Trump's request.

"Why does a president get rid of the prosecutor for the southern district of New York that he himself chose on a Friday night, less than five months from the" presidential election of November 3 ?, Bharara asked on Twitter.

Barbara McQuade, a former prosecutor and professor of law at the University of Michigan, explained to AFP that "because Berman was appointed by the court, if Trump fires him, he can only be replaced by the court or by a person confirmed by the US Senate."

"One question that may be asked is whether the president is constitutionally empowered to directly fire a court-appointed US attorney," said Professor Shane.

"It is an open question, but our current Supreme Court is so deferential with the presidential authority that it could well allow a dismissal of this type if Trump dismisses Berman, and if Berman decides to sue him to remain in office," said this separation expert. of powers.