WASHINGTON – In a Friday evening court filing, acting White House Chief of Staff Mick Mulvaney asked to join a lawsuit aiming to force federal courts to decide on whether White House officials have to testify in the impeachment inquiry of President Donald Trump.
Mulvaney, who witnesses have placed at the center of the Ukraine controversy, had been scheduled to testify in the impeachment inquiry Friday morning, and was subpoenaed on Thursday, but defied the subpoena. His lawyer cited "absolute immunity" from testifying, a protection Democratic lawmakers have dismissed.
Kupperman defied a House subpoena on Monday while awaiting the decision because he worried any decision he makes "will inflict grave Constitutional injury on either the House or the President," as stated in the lawsuit.
The lawsuit, had originally been filed on Oct. 25 by Charles Kupperman, a deputy to former National Security Adviser John Bolton.
Kupperman’s 17-page filing says that if he defies Trump, he could hurt the president's ability to receive confidential advice from top aides. Trump, who called the inquiry a partisan "witch hunt," vowed to fight all subpoenas.
Kupperman ended up defying a House subpoena in October while awaiting the decision because he worried any decision he makes "will inflict grave Constitutional injury on either the House or the President," as stated in the lawsuit.
Mulvaney's lawyers argued their intervention in the lawsuit would lead to a ruling clarifying whether officials needed to comply with subpoenas or with White House instructions not to testify.
"The question whether the President’s authority must give way in the face of a congressional subpoena—the determination Mr. Kupperman has asked this Court to make—is central to the question whether the House may take adverse action against Mr. Mulvaney, as threatened," Mulvaney's attorneys wrote.
On Tuesday, House Democrats withdrew their subpoena of Kupperman, seeking to quickly dismiss the lawsuit.
A decision in the lawsuit could also have ramifications for the potential testimony of Bolton. His lawyer, Charles Cooper, said in a Friday letter to House Democrats that Bolton would testify if a decision were reached in the Kupperman lawsuit.
"Dr. Kupperman stands ready, as does Ambassador Bolton, to testify if the Judiciary resolves the conflict in favor of the Legislative Branch’s position respecting such testimony," Cooper wrote on Friday.
According to Cooper, Bolton has information about many as-yet-undisclosed "meetings and conversations" related to the Ukraine investigation.
Mulvaney has emerged as a central character in the controversy around the Trump administration's pressuring of the Ukrainian government to open investigations into Trump's political adversaries.
Mulvaney said during an Oct. 17 press conference that Trump withheld military aid to Ukraine in order to encourage an investigation into U.S. domestic politics, though he later issued a statement saying there was no quid pro quo to provide aid in exchange for an investigation of the 2016 election.
Contributing: Bart Jansen, Deirdre Shesgreen, Kristine Phillips
This article originally appeared on USA TODAY: Trump impeachment probe: Mick Mulvaney seeks to join subpoena lawsuit