A senior aide to President Biden on Wednesday announced he will refuse to appear before a House committee investigating a potential cover-up of the president’s mental health decline, drawing a stern rebuke from the committee’s Republican chairman.

Anthony Bernal, former assistant to the president and senior adviser to first lady Jill Biden, was set to appear on Thursday. The White House on Tuesday revoked executive privilege for the former aide, which prompted his lawyers to announce he would no longer appear for the interview.

“Anthony Bernal — Jill Biden’s so-called ‘work husband’ — never intended to be transparent about Joe Biden’s cognitive decline and the ensuing cover-up,” House Committee on Oversight and Government Reform Chairman James Comer said in a statement. 

“With no privilege left to hide behind, Mr. Bernal is now running scared, desperate to bury the truth. The American people deserve answers and accountability, and the Oversight Committee will not tolerate this obstruction. I will promptly issue a subpoena to compel Anthony Bernal’s testimony before the Committee,” Mr. Comer said.

Mr. Bernal’s late decision follows the testimony before the committee from Neera Tanden, the former staff secretary who controlled the Biden autopen. She  admitted that she was authorized to use the automatic signature tool known during the president’s time in office, but said she did not know who in the inner circle ran the operation.

Ms. Tanden, who testified for five hours on Tuesday behind closed doors in a House Oversight Committee hearing, served as the director of Biden’s Domestic Policy Council and as a senior adviser. She told lawmakers that the approval mechanisms for use of the autopen were inherited from prior administrations, but described an unclear process regarding who ultimately authorized their usage, according to an Oversight Committee official who spoke with Fox News.

The former aide was combative in her opening statement to committee members, according to prepared opening remarks obtained by Politico.

“My cooperation should not be taken to mean that I think the Committee’s ‘investigation’ is a worthy subject of oversight,” Ms. Tanden said. “I do not believe it is.”

During her role between 2021 and 2023, Ms. Tanden’s responsibility involved sending decision memos to Mr. Biden’s senior staff, seeking clearance for autopen use. However, she said she was not privy to the steps or approvals that took place from the time the memos were sent until they were finalized. 

“As staff secretary, I was responsible for handling the flow of documents to and from the president,” she said. “I was also authorized to direct that autopen signatures be affixed to certain categories of documents. We had a system for authorizing the use of the autopen that I inherited from prior administrations. We employed that system throughout my tenure as staff secretary.”

Sources familiar with the testimony noted that Ms. Tanden, despite her authorization to direct autopen usage, had limited interactions with Mr. Biden himself. She emphasized that much of the decision-making process remained beyond her pay grade.

“She explained that to obtain approval for autopen signatures,” Mr. Comer said, “she would send decision memos to members of the President’s inner circle and had no visibility of what occurred between sending the memo and receiving it back with approval. Her testimony raises serious questions about who was really calling the shots in the Biden White House amid the President’s obvious decline.”

Lawmakers questioned Ms. Tanden about Mr. Biden’s physical and mental fitness during her tenure as an aide, including the period following his debate performance that was widely criticized last summer. When asked if she had discussed the president’s health or fitness for office, Ms. Tanden denied having such conversations with any officials on a list provided by lawmakers. “No,” she stated in response to each name put forth during the session, the committee official told Fox.

Emerging from her testimony at the Capitol, Ms. Tanden expressed her willingness to assist with the inquiry, saying, “I just spoke with the House Oversight Committee, Majority and Minority Council. I answered every question, was pleased to discuss my public service, and it was a thorough process. And I’m glad I answered everyone’s question.”

When pressed about whether there had been any efforts to conceal Mr. Biden’s mental and physical condition, Ms. Tanden said, “absolutely not.”

Before her testimony, the Trump administration waived Ms. Tanden’s executive privilege, according to a letter to Ms. Tanden obtained by Politico. “In light of the unique and extraordinary nature of the matters under investigation, President Trump has determined that an assertion of executive privilege is not in the national interest, and therefore is not justified,” Gary Lawkowski, deputy counsel to Mr. Trump, said in the letter.

President Trump has called into question the validity of pardons issued by his predecessor, describing them as “VOID, VACANT, AND OF NO FURTHER FORCE OR EFFECT” in an X post. Mr. Trump suggested that Mr. Biden was unaware of the decisions being made at the time, saying, “He did not know anything about them!” 

Hours before Mr. Trump took the oath of office on Jan. 20, 2024, the Biden White House announced pardons for Dr. Anthony Fauci, the former director of the National Institute of Allergy and Infectious Diseases,  and Army Gen. General Milley, the former chairman of the Joint Chiefs of Staff. 

With less than 30 minutes in his term, Mr. Biden pardoned members of his family, including his brother James B. Biden, his wife, Sara, sister Valerie Biden Owens, brother-in-law John T. Owens and brother Francis W. Biden. The former president had pardoned his son, Hunter, for tax and gun crimes a month earlier.

Congress’s investigation continues to scrutinize the use of autopen signatures and Mr. Biden’s decision-making processes, signaling broader implications regarding transparency within the administration. With additional depositions planned, including those from medical and senior administrative officials, lawmakers appear committed to addressing both procedural and ethical concerns tied to these revelations. 

Republicans have subpoenaed Dr. Kevin O’Connor, the former president’s personal physician, to appear July 9 for questioning about Mr. Biden’s health records. Furthermore, the Committee intends to hear from other key members of Mr. Biden’s inner circle, including Annie Tomasini, Biden’s former deputy chief of staff, and Ashley Williams, former deputy director of Oval Office operations.