Republican Sen. Chuck Grassley on Wednesday asked President Biden not to "fire all of President Trump’s U.S. Attorneys" amid ongoing investigations, after the Justice Department said this week that Trump-era federal prosecutors would be forced to resign from their posts by the end of the month, urging him to "take the time and do it right." 

Grassley, R-Iowa, penned a letter to the president Wednesday, saying that Biden is "obviously within your rights to do this, but four years ago a similar action by then-Attorney General Sessions caused my Democratic colleagues to sound the alarm."

BIDEN DOJ WANTS DC'S ACTING US ATTORNEY TO STAY ON IN SPECIAL PROSECUTOR ROLE TO CONTINUE CAPITOL RIOT PROBE

Grassley pointed to Senate Democrats urging Trump not to interrupt ongoing cases and investigations, claiming he was "hindering the administration of justice."

"I echo many of these concerns," Grassley wrote. "It is unfortunate that you are taking these actions without replacements announced. It is also concerning that your administration did not consult with home-state Senators about this decision and that some of these U.S. Attorneys may be involved in sensitive investigations."

Grassley specifically pointed to U.S. Attorney John Lausch in the Northern District of Illinois, who is supervising the ComEd public corruption investigation in the state – a "significant bribery case," Grassley said, which is "said to potentially implicate longtime Illinois House Speaker Mike Madigan."

Federal prosecutors last year said utility company ComEd admitted to providing jobs or contracts "for various associates of a high-level elected official for the state of Illinois." While Madigan's name was not mentioned, a federal court filing identifies the official as the Illinois House speaker.

Prosecutors claim that the purpose of the alleged scheme was "to influence and reward the official’s efforts to assist ComEd with respect to legislation concerning ComEd and its business." In a news release, the U.S. Attorney's Office said "Public Official A" influenced lawmakers regarding legislation that impacted ComEd. At this time, Madigan has not been charged and has not been formally accused of wrongdoing.

The $200 million fine for ComEd is part of a deferred prosecution agreement the company signed. The investigation of the alleged scheme continues, and Madigan's office confirmed that he has received subpoenas for documents related to job recommendations, while insisting that he did nothing wrong.

Madigan has served in the state legislature since 1971. He first assumed the role of speaker in 1983, and has held the position ever since, with the exception of two years when Democrats lost their majority. He is the longest-serving state House speaker in the country. His daughter Lisa also served as state attorney general.

"Mr. Madigan, of course, is widely regarded as the Democratic political 'boss' of Illinois and an ally of former President Obama," Grassley wrote. "It is therefore especially important that this investigation be allowed to proceed in a way that does not even provide the appearance of political interference from Washington."

Grassley went on to state that Biden is "the President and the President is, as a rule, entitled to an administration."

BIDEN DOJ ASKS TRUMP-APPOINTED US ATTORNEYS TO RESIGN BY END OF THE MONTH

"This includes the Department of Justice. But in the interest of the rule of law and the confidence of the American people in the law's impartial application, I would urge you not to simply fire all of President Trump's U.S. Attorneys except for the two most obviously sensitive – Durham and Weiss," Grassley said.

"Take the time to do it right. See who has important investigations ongoing – like Lausch – and make sure that the American People have confidence in the independence of the Department of Justice," Grassley said.

A senior Biden administration official told Fox News on Tuesday that 56 U.S. attorneys have until Feb. 28 to resign – with the exception of U.S. Attorney David Weiss in Delaware, who has oversight of the federal probe into Hunter Biden’s "tax affairs," and Special Counsel John Durham, who is investigating the Russia probe. Durham will resign from his post as U.S. attorney, but will be able to continue his investigation as special counsel.

"We are committed to ensuring a seamless transition," acting Attorney General Monty Wilkinson said in a statement. "Until U.S. Attorney nominees are confirmed, the interim and acting leaders in the U.S. Attorneys’ Offices will make sure that the department continues to accomplish its critical law enforcement mission, vigorously defend the rule of law, and pursue the fair and impartial administration of justice for all."

The Justice Department said that earlier this year, "nearly all presidential appointees from the previous administration offered their resignations, though U.S. Attorneys and U.S. Marshals were asked to temporarily remain in place."

The DOJ said that before the beginning of the transition process, approximately one-third of the U.S. Attorneys’ Offices were already led by acting or interim leadership.

The Justice Department said the president will make an announcement regarding nominations to the Senate "as that information becomes available."

White House press secretary Jen Psaki on Tuesday was asked about Weiss and Durham, and said those "decisions were made in order to fulfill his promise of maintaining independence."

Fox News has also learned that the Justice Department wants acting U.S. Attorney for the District of Columbia Michael Sherwin to leave his post at the U.S. Attorneys’ Office in D.C., but to transition to main Justice to serve in some type of special prosecutor capacity to continue overseeing the Capitol breach investigation.

Sherwin has had oversight of the prosecutions stemming from the Capitol riot on Jan. 6.

Sherwin has vowed to "bring the most maximum charges we can based upon the conduct."

Overall, federal authorities have charged more than 150 people in the Capitol siege.

Last week, South Carolina Sen. Lindsey Graham, the top Republican on the Senate Judiciary Committee, urged Wilkinson to "refrain from interfering" in Durham’s investigation and the federal investigation into Hunter Biden’s "tax affairs" while the Senate works to confirm Biden’s nominee to lead the Justice Department.

The Senate is currently processing the nomination of Judge Merrick Garland to the position of attorney general.