By Sarah N. Lynch, David Morgan and Steve Holland
WASHINGTON (Reuters) - U.S. President Donald Trump on Monday told former White House counsel Don McGahn to defy a subpoena to testify about the Russia investigation before a congressional committee, deepening a fight between the administration and Democratic lawmakers.
In a letter to the House of Representatives Judiciary Committee's Democratic Chairman Jerrold Nadler, White House Counsel Pat Cipollone said that McGahn should not appear due to both "constitutional immunity" and "in order to protect the prerogatives of the Office of the Presidency."
The committee is investigating whether Trump illegally obstructed the probe into Russian interference in the 2016 presidential election.
McGahn figured prominently in a report by Special Counsel Robert Mueller about the Russia probe and whether Trump committed obstruction of justice.
The report cites McGahn as saying that Trump called him several times in June 2017 to tell him to direct the Justice Department to remove Mueller because of conflicts of interest.
McGahn did not carry out Trump’s order, the report said. Later, when news articles about the incident surfaced, McGahn told Mueller's investigators that Trump tried to get him to dispute the accuracy of the reports. McGahn again refused.
Many Democratic lawmakers, as well as many former prosecutors not involved in the investigation, have said that the alleged order by the president to fire Mueller and attempt to coerce McGahn to lie about it could amount to committing the crime of obstruction.
Trump has denied asking McGahn to have Mueller removed.
House Democrats have sought McGahn's cooperation as part of their investigation of possible corruption and obstruction of justice by Trump. Trump denies wrongdoing.
Congressional aides said on Monday that the committee has not yet been formally notified by McGahn and his attorney about whether he will attend the proceedings, though Nadler intends to still go ahead with the hearing regardless.
An attorney for McGahn could not be reached for comment. It was not immediately clear whether McGahn could still appear in front of the panel, but decline to answer questions. McGahn might be held in contempt of Congress if he refuses to testify.
Mueller's report described numerous links between Trump's 2016 campaign and various Russians but did not find sufficient evidence to establish there was a criminal conspiracy with Moscow.
The report also described numerous attempts by Trump to impede Mueller's investigation, but stopped short of declaring the president had committed a crime.
Attorney General William Barr determined after reviewing Mueller's findings that there was insufficient evidence to bring criminal obstruction charges against the president.
Nadler's committee has been locked in multiple battles with the Trump administration over access to information contained in the Mueller report.
Trump said following the release of the Mueller report in March that it showed he was exonerated of colluding with Russia and obstruction justice.
But since then he has hardened his administration's position of defying the legal demands of Democrats in Congress who want more information on the Russia investigation and Trump’s taxes and business dealings.
Earlier this month, the committee voted to hold Barr in contempt after he defied a subpoena seeking an unredacted copy of the Mueller report and its underlying investigative materials.
Nadler also issued a subpoena last month compelling McGahn to testify on Tuesday, and he has previously said he would hold the attorney in contempt if he did not show up.
Congressional aides said Tuesday’s hearing date for McGahn would enable Democrats to mark up a contempt citation against him as early as Thursday.
The Justice Department's Office of Legal Counsel, meanwhile, issued an opinion on Monday that gave legal cover to the decision to block McGahn from testifying.
In it, Justice Department Assistant Attorney General Steven Engel wrote that, "Congress may not constitutionally compel the President's senior advisers to testify about their official duties."
(Reporting by Steve Holland, Sarah N. Lynch, David Morgan and Tim Ahmann; writing by Mohammad Zargham; editing by Jonathan Oatis and Alistair Bell)