As Sessions tried to push Wray to make personnel changes, Wray conveyed his frustration to the attorney general, these people said. Sessions then discussed the matter with McGahn, who advised him to ease off, which he did, these people said.
One person familiar with the discussions said Wray has not addressed FBI personnel matters with the president, but in December, after The Washington Post reported that McCabe planned to retire in March when he becomes eligible for his full pension benefits, Trump tweeted about his criticisms of McCabe, a target of his since the 2016 presidential campaign.
Much of the discussion between Wray and Sessions about housecleaning at the FBI also came in December, according to people familiar with the matter.
Axios was first to report the Session-Wray dispute on Monday evening, indicating that Wray had threatened to resign if Sessions did not stop pressuring him to fire McCabe. But several people familiar with the dynamic told The Post that they were not aware of Wray making such an explicit threat. Firing McCabe could be problematic because he has limited civil service protections as a government employee. Such a move, in the aftermath of public criticism from the president and others, could prompt litigation.
Spokesmen for the FBI and Justice Department declined to comment.
In a statement, White House spokesman Raj Shah praised Wray while attacking other senior FBI officials.
"The President has enormous respect for the thousands of rank-and-file F.B.I. agents who make up the world's most professional and talented law enforcement agency. He believes politically motivated senior leaders, including former Director Comey and others he empowered, have tainted the agency's reputation for unbiased pursuit of justice,'' said Shah. "The president appointed Chris Wray because he is a man of true character and integrity, and the right choice to clean up the misconduct at the highest levels of the F.B.I. and give the rank and file confidence in their leadership."
Wray has sought to avoid the drama and personal confrontations that sometimes flare inside the Trump administration. In public comments and private remarks to FBI personnel, Wray has signaled that staffing decisions are his to make, and that he intends to wait for an ongoing inspector general's investigation to reach some conclusions before making major personnel decisions involving people under scrutiny — a category that includes McCabe.
Sessions, Republican lawmakers and some members of the Trump administration have argued for weeks that Wray should conduct some kind of housecleaning by demoting or reassigning senior aides to his predecessor, Comey, according to people familiar with the matter. These people added that Sessions himself is under tremendous political pressure from conservative lawmakers and White House officials who have complained that the bureaucracy of federal law enforcement is biased against the president.
Wray became FBI director in August, taking the helm of the nation's premier law enforcement agency at a turbulent time — under frequent attack from congressional Republicans and occasionally the president, and facing a wide-ranging internal investigation into how it handled politically sensitive probes into presidential candidates Hillary Clinton and Donald Trump.
The president fired Comey in May, leading to the appointment a week later of a special counsel to investigate Trump and his associates for possible election-season coordination with agents of the Russian government. The probe is also trying to determine whether the president or any White House officials sought to obstruct justice leading up to Comey's firing.
On Monday night, Comey appeared to cheer the news that Wray was standing up to the administration, tweeting: "Good to read reports of people standing up for what they believe in."
Matt Zapotosky contributed to this report.