Jan. 6 Panel Says It Has New Evidence of Trump’s Pressure on Justice Dept.

WASHINGTON — The House committee investigating the Jan. 6 attack on the Capitol plans to unveil new evidence on Thursday about how President Donald J. Trump tried to manipulate the Justice Department to help him cling to power after he lost the 2020 election, aides said on Wednesday.

At its public hearing this month, scheduled for 3 pm on Thursday, the panel plans to hear testimony from three former top justice department officials who are expected to lay out the ways in which Mr. Trump tried to misuse the attorney general’s office to overturn his defeat, an extraordinary instance of a president interfering with the nation’s law enforcement apparatus for his own personal ends.

Committee aides said the panel would detail how Mr. Trump unsuccessfully pushed department officials to falsely declare that there was widespread fraud in the election, file lawsuits to benefit his campaign and appoint a conspiracy theorist as a special counsel to investigate the election. It will also trace his failed efforts to send false letters to state officials to subvert the election results and, finally, to replace the acting attorney generalwho refused to go along with his plans.

Mr. Trump ultimately backed off after agency officials threatened mass resignations, but the committee is presenting his actions as a critical strand in a multilayered effort by the former president to subvert the election.

The witnesses scheduled to testify are Jeffrey A. Rosen, the former acting attorney general; Richard P. Donoghue, the former acting attorney general; and Steven A. Engel, the former assistant attorney general for the Office of Legal Counsel.

Representative Adam Kinzinger, a Republican of Illinois and a member of the committee, is expected to play a central role in the questioning of witnesses and presentation of evidence. He has hinted that the hearing could reveal more information about members of Congress who sought pardons after Jan. 6.

The story of how Mr. Trump attempted to intervene in the workings of the Justice Department to keep himself in office has been well documented by both the Senate Judiciary Committee and the House Jan. 6 committee, but aides to the House inquiry said Thursday’s hearing will contain new revelations.

Time and again, department officials told Mr. Trump after the election that his claims of widespread fraud were false, and prompted him to back down from some of his most extreme propositions.

One dramatic moment came in an Oval Office meeting on Jan. 3, 2021, when Jeffrey Clark, a little-known department lawyer who had been strategizing about how to keep Mr. Trump in power, suggested that the agency issue a legal opinion to Vice President Mike Pence advising him as to what actions he could take during the joint session of Congress set for three days later, when lawmakers were to meet for the official electoral count that would Confirm Joseph R. Biden Jr.’s victory.

“That’s an absurd idea,” Mr. Engel interjected, according to the testimony he provided to the commission. “It is not the role of the Department of Justice to provide officials with legal advice on the scope of their duties.”

Mr. Trump then spoke up and told the Justice Department officials, who repeatedly told him his claims of widespread fraud were false, that they were not to speak to Mr. Pence.

“Nobody should be talking to the vice president here,” Mr. Trump said, according to Mr. Engel.

Mr. Trump would go on to repeatedly push Mr. Pence to try to overturn the election results.

Also at that meeting, Mr. Trump proposed firing Mr. Rosen, who was advising him that the 2020 election was not stolen, and replacing him with Mr. Clark, who was willing to do his bidding.

“Sir, I would resign immediately,” Mr. Donoghue spoke up, according to a deposition he gave. “There is no way I’m serving one minute under this guy,” he said of Mr. Clark.

Mr. Trump then turned to Mr. Engel and said, “Steve, you wouldn’t resign, would you?” Mr. Engel replied: “Absolutely I would, Mr. President. You’d leave me no choice.”

The Justice Department officials were also witnesses to interactions between Pat A. Cipollone, the White House counsel, and Mr. Trump. The committee has called for Mr. Cipollone to testify publicly, but he has so far refused.

Mr. Cipollone pushed back against a plan put forward by Mr. Clark, who wanted to distribute official letters to multiple state legislatures falsely alerting them that the election may have been stolen and urging them to reconsider certified election results.

“That letter that this guy wants to send — that letter is a murder-suicide pact,” Mr. Cipollone told Mr. Trump, according to Mr. Donoghue. “It’s going to damage everyone who touches it. And we should have nothing to do with that letter. I don’t ever want to see that letter again.”

The panel is planning at least two more hearings for July, according to its chairman, Representative Bennie Thompson, Democrat of Mississippi. Those sessions are expected to detail how a mob of violent extremists attacked Congress and how Mr. Trump did nothing to call off the violence for more than three hours.