Atkinson will leave his job in 30 days, Trump told the House and Senate Intelligence committees, and he has been placed on administrative leave effective immediately, according to a congressional source.
Trump did not name a permanent successor.
“As is the case with regard to other positions where I, as President, have the power of appointment … it is vital that I have the fullest confidence in the appointees serving as inspectors general,” Trump wrote. “That is no longer the case with regard to this Inspector General.”
Atkinson’s firing is the latest case of the Trump administration removing officials who took part in the President’s impeachment. Trump also removed Alexander Vindman, a then-National Security Council official who had testified in the House’s proceedings, along with Vindman’s twin brother, both of whom were reassigned out of the NSC, and fired then-US Ambassador to the European Union Gordon Sondland.
Other officials, including then-US Ambassador to Ukraine Marie Yovanovitch and her acting successor, Bill Taylor, left the Trump administration after the impeachment proceedings.
Trump also fired former FBI Director James Comey in 2017 while the FBI was investigating the President.
The congressional source said that Atkinson was informed on Friday evening that Trump had fired him. The statute for the intelligence community inspector general requires that both intelligence committees be notified 30 days before the inspector general can be dismissed, so Trump could not immediately remove Atkinson — he could only place him on leave until the 30 days pass.
Top Democrats on the House and Senate Intelligence committees blasted the move.
House Intelligence Chairman Adam Schiff of California, who led the House’s impeachment investigation, said the firing was “another blatant attempt by the President to gut the independence of the Intelligence Community and retaliate against those who dare to expose presidential wrongdoing.”
“This retribution against a distinguished public servant for doing his job and informing Congress of an urgent and credible whistleblower complaint is a direct affront to the entire inspector general system,” Schiff said in a statement.
Virginia Sen. Mark Warner, the top Democrat on the Senate Intelligence Committee, said, “In the midst of a national emergency, it is unconscionable that the President is once again attempting to undermine the integrity of the intelligence community by firing yet another an intelligence official simply for doing his job.”
Atkinson — a career, nonpartisan official — came under fire from the President’s allies last year for alerting lawmakers to the then-unknown whistleblower complaint, which Congress later learned was an allegation that Trump had sought dirt on his political rival former Vice President Joe Biden from Ukraine’s President while withholding US security aid from Kiev.
The allegation sparked a House impeachment inquiry that detailed the quid pro quo effort and led to Trump’s impeachment in December on two articles. The Senate acquitted Trump on both charges in February.
Atkinson said he had shared the complaint with Congress because he found it rose to the level of an “urgent concern,” clashing with his boss, then-acting Director of National Intelligence Joseph Maguire, over the determination.
After the whistleblower complaint was shared with Congress, Atkinson testified before the intelligence committees, explaining how he had attempted to corroborate the complaint in order to determine it was credible and should be shared with Congress. Maguire initially pushed back on that recommendation, but the White House ultimately relented and released the complaint.
Other top intelligence officials also have recently left the administration, after Trump picked US Ambassador to Germany Richard Grenell to replace Maguire as acting director of national intelligence. Russ Travers, who was head of the National Counterterrorism Center, was fired last month by Grenell in a move that was seen as a removal of someone not perceived as loyal enough.
Tom Monheim, a career intelligence official, will be the acting intelligence community inspector general, according to the Office of the Director of National Intelligence.
This story has been updated with additional reporting.
CNN’s Zachary Cohen, Alex Marquadt, Manu Raju and Phil Mattingly contributed to this report.