Special Counsel Set to Rebut Claims of Favoritism Toward Hunter Biden

David C. Weiss, who negotiated an ill-fated plea deal with President Biden’s son Hunter, is set to defend his investigation before the House Judiciary Committee on Tuesday, the first time a special counsel has agreed to field queries from Congress before concluding an inquiry.

Mr. Weiss, the Trump-appointed U.S. attorney in Delaware, plans to use the interview to counter claims that he brokered a sweetheart deal with Hunter Biden under pressure from the White House. He is also set to dispute a whistle-blower’s allegation that he once complained that he had not been given full authority to prosecute Hunter Biden on tax charges.

The special counsel “is prepared to take this unprecedented step of testifying before the conclusion of his investigation to make clear that he’s had and continues to have full authority over his investigation and to bring charges in any jurisdiction,” according to his spokesman, Wyn Hornbuckle.

House Republicans have made their charges of favorable treatment for Mr. Biden a key piece of their sputtering efforts to impeach the president. Their theories have remained unsupported — and often directly contradicted — by the evidence.

Mr. Weiss is not expected to discuss the federal investigation into Mr. Biden’s lucrative foreign business dealings, or his recent indictment of Mr. Biden on three charges related to his illegal purchase of a handgun in 2018, when he was addicted to drugs and alcohol, Mr. Hornbuckle said.

“Consistent with department policy and the law, he will be unable to address the specifics of his investigation,” Mr. Hornbuckle said.

Mr. Weiss was appointed by President Donald J. Trump as the U.S. attorney for Delaware in 2018 and subsequently retained by Attorney General Merrick B. Garland to finish the Hunter Biden investigation.

He has privately fumed over Republican allegations that he expressed frustrations with federal prosecutors in Washington and Los Angeles for refusing to partner with him in bringing felony tax charges against the president’s son in their jurisdictions, according to people familiar with the situation.

Representative Jim Jordan, the Ohio Republican who is the chairman of the committee, had negotiated with the Justice Department for weeks over the terms of Mr. Weiss’s testimony. The department offered Mr. Jordan the option of a public hearing, but the committee opted for a private session, as it has done after recent interviews with the federal prosecutors who declined to bring charges against the president’s son, according to department officials.

Mr. Jordan, who ran unsuccessfully for House speaker last month, has repeatedly suggested that Mr. Weiss and Mr. Garland have misled his committee.

“David Weiss said repeatedly that he had ‘ultimate authority’ over the decision to charge Hunter Biden,” Mr. Jordan said in a post on X, formerly known as Twitter. “The only problem? He didn’t. And witnesses continue to discredit his narrative.”

Over the summer, House Republicans released testimony from a senior Internal Revenue Service investigator on the case that appeared to contradict Mr. Garland’s public assurances that Mr. Weiss had the freedom and authority he needed to pursue the case as he saw fit.

The I.R.S. official, Gary Shapley, oversaw the agency’s role in investigating Mr. Biden’s taxes. Mr. Shapley said his criticism of the Justice Department led to his being denied a promotion. He told the House Ways and Means Committee that Mr. Weiss, during a meeting with the Biden investigative team on Oct. 7, 2022, said he was considering seeking special counsel status to give him more authority to bring cases outside of Delaware.

Several people present at that meeting, including Mr. Weiss, have disputed Mr. Shapley’s version of events.

Mr. Weiss had expected to be done with the Hunter Biden case by now. In the spring, after five years of work, he negotiated a complex agreement with Mr. Biden’s legal team that spared the president’s son jail time in exchange for pleading guilty to misdemeanor tax charges and participation in a two-year program for nonviolent firearms offenders.

But the deal blew up during a fractious court hearing in late July. Shortly after, Mr. Weiss indicted Mr. Biden on gun charges, to which he pleaded not guilty.

Prosecutors also announced they intended to continue their investigation of his business dealings, possibly in connection with violations of laws governing lobbying for foreign countries and businesses.

In August, Mr. Weiss requested to be appointed special counsel, and Mr. Garland — who had previously said that doing so was unnecessary — elevated him. Mr. Garland said he would publicly release Mr. Weiss’s report after the investigation concluded.