From today's WSJ:

WASHINGTON — The White House counsel, Donald F. McGahn II, will be leaving the administration this fall, President Trump tweeted Wednesday morning, leaving the president’s side just as the sprawling investigation into Russian election interference could come to a conclusion.

In addition to stripping the White House of another top official, Mr. McGahn’s departure may fuel concerns about how the president has interacted with witnesses and potential witnesses in the Russia inquiry. Mr. McGahn is a key witness to whether the president tried to obstruct the investigation.

The departure of the top lawyer in the White House has been rumored for months. In his tweet, Mr. Trump said that Mr. McGahn would leave after the Senate votes on the confirmation of Judge Brett Kavanaugh to fill the vacant seat on the Supreme Court later this fall.