Don McGahn, the White House counsel who reportedly spent 30 hours in interviews with the Russian election meddling probe, is to leave his post this autumn.
The news was announced by Donald Trump, the US president, in a tweet on Wednesday after Mr McGahn’s imminent departure was reported by the political news website Axios.
It ushers in a new phase of uncertainty for the president’s legal team at a time when Robert Mueller, the man leading the Russia investigation, is seeking an interview with Mr Trump.
Mr Trump tweeted: “White House Counsel Don McGahn will be leaving his position in the fall, shortly after the confirmation (hopefully) of Judge Brett Kavanaugh to the United States Supreme Court. I have worked with Don for a long time and truly appreciate his service!”
Mr McGahn has led the White House’s successful drive to install conservative judges at all levels of the American legal system since Mr Trump took office last year.
He has already overseen the successful appointment of one Supreme Court judge, Neil Gorsuch, and hopes another, Brett Kavanaugh, will be approved next month.
However as a central figure in the White House’s legal team, Mr McGahn has also been involved in how Mr Trump has dealt with Robert Mueller, the special counsel investigating Russian meddling in the 2016 US election.
A spat between Mr McGahn and other White House lawyers about how co-operative to be towards Mr Mueller spilled out in the open last year when some were overheard by a reporter discuss the tensions over lunch.
Mr McGahn was said to oppose full co-operation with Mr Mueller while two other senior lawyers disagreed. The White House ended up co-operating, handing over thousands of emails and documents to investigators.
However that stance has been called into question in recent months as Mr Trump has adopted a far more combative stance towards Mr Mueller, calling for the probe to be shut down and attacking his staff as "angry democrats".
Earlier this month, The New York Times reported that Mr McGahn – who has been with Mr Trump since the 2016 presidential campaign – has talked to Mr Mueller’s team for a total of 30 hours and that the White House was not fully briefed on what he had said.
The report said that Mr McGahn has discussed topics at the heart of Mr Mueller’s probe, including providing information that investigators did not yet know.
It raised questions about whether Mr McGahn was working to protect himself from legal jeopardy rather than the president – something played down by the White House.
Mr Trump was reportedly left blind-sided by the news. He tweeted at the time that he was aware Mr McGahn had talked to the Mueller probe.
However less than two weeks after that report, Mr McGahn’s departure has now been announced.
There was an immediate response from some on Capitol Hill.
Chuck Grassley, the Republican senator and chair of the Senate Judiciary Committee, tweeted a message to Mr Trump that said: “I hope it’s not true McGahn is leaving White House Counsel. U can’t let that happen.”
Mitch McConnell, the Senate Republican leader, praised Mr McGahn as "the most impressive White House Counsel during my time in Washington".
Asked about the news in the White House, Mr Trump praised Mr McGahn as an “excellent guy” and said he was not concerned about his discussions with the Mueller probe.
Mr McGahn was reportedly surprised by the tweet and had not been warned in advance, but he had been planning his departure and discussing it with figures inside the White House.
Axios, which first reported Mr McGahn’s departure, said that he could be replaced Emmet Flood, a lawyer who once worked with Bill Clinton’s administration and joined the White House in May.
Whoever takes Mr McGahn’s place may have to deal with a wave of requests from congressional investigations if the Democrats take control of the House of Representatives in the November midterm elections, as many have predicted.
They will also be stepping into long-running negotiations about whether Mr Trump will agree to Mr Mueller’s request for an interview as part of the Russia probe.
Mr Mueller reportedly wants to ask Mr Trump about claims of obstruction of justice. He has been seeking an interview since the start of the year but it is yet to happen.