The Trump Justice Department faced tough questioning Friday from a federal appeals court over a political and legal standoff with the House Judiciary Committee, dealing with a pair of interrelated disputes that could impact the current and future impeachment proceedings against the president.

A three-judge panel in Washington presided over about three hours of public arguments, hearing from lawyers representing the executive and legislative branches, including over efforts to compel testimony from former White House counsel Donald McGahn.

HOUSE DEMS RAISE PROSPECT OF NEW IMPEACHMENT ARTICLES, IN COURT BATTLE OVER MCGAHN TESTIMONY

At issue is whether judges should be settling a dispute between the two branches over information requested by Congress, dealing with a subpoena of a former White House official, and unredacted grand jury material from the Mueller investigation into Russian meddling in the 2016 election.

The president has told his aides not to cooperate with a congressional impeachment inquiry, said Judge Thomas Griffith, an appointee of President George W. Bush. "Has that ever happened before? No it hasn't," he said.

Griffith said the White House was engaging in a "broad-scale defiance of a congressional investigation."

The Democrat-led House committee wants testimony from McGahn, which lawmakers suggested could be relevant to the impeachment trial pending in the Senate.

But Justice Department lawyers argued McGahn left his post before the July Trump phone call with the Ukrainian president that is at the heart of the impeachment articles.

Griffith and Judge Neomi Rao, a Trump bench appointee, questioned the House's need for McGahn's testimony at this stage. And they suggested this matter may be best left for the other branches to work out among themselves, with a measure of compromise and accommodation, as is usually done with such disputes.

And Judge Karen Henderson, named to the court by President George H.W. Bush, suggested even if McGahn were compelled to appear before the House committee, he might not say much, citing attorney-client privilege to protect sensitive conversations with the president.

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Trump is charged with abuse of power and obstruction of Congress over his alleged efforts to tie Ukrainian military aid to that country's promise to investigate his potential political rival Joe Biden, the former vice president.

House lawyers told the judges that "absolutely" the McGahn subpoena and the Mueller grand jury information could be relevant to current and future impeachment proceedings. House General Counsel Douglas Letter told the court the White House's efforts to defy Congress were "so clearly wrong."

But Justice Department lawyers said not only should judges not get involved in these cases, but the issue is currently moot, since Trump is about to face a Senate trial without McGahn's testimony being used by the House.

Rulings are expected in several weeks, and the Supreme Court could then be asked to get involved. It is unclear how any high court final decision would impact the current impeachment drama unfolding on Capitol Hill.