WASHINGTON (AP) — The House Judiciary Committee is poised to question former White House counsel Don McGahn behind closed doors on Friday, two years after House Democrats originally sought his testimony as part of investigations into former President Donald Trump.

The long-awaited interview is the result of an agreement reached last month in federal court. House Democrats — then investigating whether Trump tried to obstruct the Justice Department’s probes into his presidential campaign’s ties to Russia — originally sued after McGahn defied an April 2019 subpoena on Trump’s orders.

That month, the Justice Department released a redacted version of special counsel Robert Mueller’s report on the matter. In the report, Mueller pointedly did not exonerate Trump of obstruction of justice but also did not recommend prosecuting him, citing Justice Department policy against indicting a sitting president. Mueller’s report quoted extensively from interviews with McGahn.

While the Judiciary panel eventually won its fight for McGahn’s testimony, the court agreement almost guarantees its members won’t learn anything new. The two sides agreed that McGahn will be questioned only about information attributed to him in publicly available portions of Mueller’s report.

Still, House Democrats kept the case going, even past Trump’s presidency, and are moving forward with the interview. House Judiciary Committee Chair Jerrold Nadler, D-N.Y., said the agreement for McGahn’s testimony is a good-faith compromise that “satisfies our subpoena, protects the Committee’s constitutional duty to conduct oversight in the future, and safeguards sensitive executive branch prerogatives.”

It is unclear what House Democrats will do with the testimony, which they sought before twice impeaching Trump. The Senate acquitted Trump of impeachment charges both times.

As White House counsel, McGahn had an insider’s view of many of the episodes Mueller and his team examined for potential obstruction of justice during the Russia investigation. McGahn proved a pivotal witness against Trump, with his name mentioned hundreds of times in the text of the Mueller report and its footnotes.

McGahn described to investigators the president’s repeated efforts to stifle the probe and directives he said he received from the president that concerned him.

He recounted how Trump had demanded that he contact then-Attorney General Jeff Sessions to order him to unrecuse himself from the Russia investigation. McGahn also said Trump had asked him to tell the deputy attorney general at the time, Rod Rosenstein, to remove Mueller from his position because of perceived conflicts of interest — and, after that episode was reported in the media, to publicly deny that demand had ever been made.

McGahn also described the circumstances leading up to Trump’s firing of James Comey as FBI director, including the president’s insistence on including in the termination letter the fact that Comey had reassured Trump that he was not personally under investigation.

And he was present for a critical conversation early in the Trump administration, when Sally Yates, just before she was fired as acting attorney general as a holdover Obama appointee, relayed concerns to McGahn about new national security adviser Michael Flynn. She raised the possibility that Flynn’s conversations with Russian Ambassador Sergey Kislyak — and his subsequent interview by the FBI — left him vulnerable to blackmail.

Trump’s Justice Department fought efforts to have McGahn testify, but U.S. District Judge Ketanji Brown Jackson in 2019 rejected Trump’s arguments that his close advisers were immune from congressional subpoena.

President Joe Biden has nominated Jackson to the appeals court in Washington.