GOP Sen. Chuck Grassley and a bipartisan group of fellow senators are calling on President Trump to provide a "detailed" written explanation for his decision to remove the intelligence community inspector general from his post, in an effort to protect watchdog independence.

In a letter to Trump, Grassley, R-Iowa, and Sens. Mitt Romney, R-Utah; Susan Collins, R-Maine; Dianne Feinstein, D-Calif.; Mark Warner, D-Va.; Jon Tester, D-Mont.; Ron Wyden, D-Ore.; and Gary Peters, D-Mich., raised concerns over Trump’s recent firing of ICIG Michael Atkinson, who played a key role in the impeachment saga.

TRUMP REMOVES INSPECTOR GENERAL POISED TO OVERSEE CORONAVIRUS RESPONSE 

“As you know, Congress created inspectors general to combat waste, fraud, and abuse, and to be the independent watchdogs holding federal agencies accountable to the taxpayer,” Grassley wrote. “To ensure inspectors general are fully capable of performing their critical duties, and in recognition of their importance both to efficient administration and to the legislative function, Congress set clear, statutory notice requirements for their potential removal.”

Under current law, the president is required to inform the Senate and House Intelligence Committees in writing of the reasoning behind the decision for a removal of an inspector general, at least 30 days prior to that removal.

“However, in your recent letter to the Senate Intelligence Committee, you stated only that, 'it is vital that [you] have the fullest confidence' in those serving as IGs and that ‘this is no longer the case’ with regard to Mr. Atkinson,” Grassley wrote, adding that Trump reportedly placed Atkinson on administrative leave, effectively removing him from his position “prior to the completion of the statutorily required notice period.”

“Congressional intent is clear that an expression of lost confidence, without further explanation, is not sufficient to fulfill the requirements of the statute,” Grassley wrote. “This is in large part because Congress intended that inspectors general only be removed when there is clear evidence of wrongdoing or failure to perform the duties of the office, and not for reasons unrelated to their performance, to help preserve IG independence.”

Grassley went on to add that it is Congress’ “responsibility to confirm that there are clear, substantial reasons for removal.”

TRUMP FIRES MICHAEL ATKINSON, IG WHO TOLD CONGRESS ABOUT TRUMP-UKRAINE CALL 

“To that end, we ask that you provide more detailed reasoning for the removal of Inspector General Atkinson no later than April 13, 2020,” Grassley wrote. “Please also provide your views on how the appointment of an acting official prior to the end of the 30 day notice period comports with statutory requirements.”

Grassley’s letter, which was signed by the group of bipartisan senators, comes days after the removal. Atkinson already had faced the president’s ire last year during the impeachment inquiry, after he alerted Congress to concerns about Trump’s fateful phone call with the president of Ukraine.

But the president seemingly has taken issue with multiple inspectors general in the last several days.

On Tuesday, the president removed Pentagon Inspector General Glenn Fine, who was tasked with monitoring the coronavirus economic relief plan via the Pandemic Response Accountability Committee, from his post.

TRUMP NOMINATES FORMER GSA WATCHDOG AS INSPECTOR GENERAL FOR CORONAVIRUS RESPONSE

“Mr. Fine is no longer on the Pandemic Response Accountability Committee,” a Pentagon spokesperson told Politico Tuesday, adding that he will return to his Senate-confirmed role as principal deputy inspector general of the Pentagon.

The president temporarily appointed the inspector general for the Environmental Protection Agency (EPA) to monitor the implementation of the new law.

The committee was part of the massive stimulus package passed last month -- a panel made up of inspectors general to locate and investigate waste and abuse of spending under the bill and in response to the crisis.

The new law also set up a new position of a special inspector general for pandemic recovery to conduct oversight over stimulus spending by the Treasury Department. On Monday, the president appointed Brian Miller to that position.

Fine’s removal comes amid a battle in Congress over Democrats' efforts to establish additional investigative committees to oversee the Trump administration’s handling of the coronavirus pandemic.

Also this week, the president blasted an inspector general official for the Department of Health and Human Services, Christi Grimm, for her Monday report that revealed severe shortages of testing supplies and extended waits for results at hospitals across the nation; widespread shortages of PPE which put staff and patients at risk; difficulty maintaining adequate staffing; and shortages of critical supplies.

“Why didn’t the I.G., who spent 8 years with the Obama Administration (Did she Report on the failed H1N1 Swine Flu debacle where 17,000 people died?), want to talk to the Admirals, Generals, V.P. & others in charge, before doing her report,” Trump tweeted Tuesday. “Another Fake Dossier!”

As for Atkinson, House Intelligence Committee Chairman Adam Schiff, D-Calif., is also "reviewing the circumstances of Mr. Atkinson’s dismissal, including whether his termination was intended to curb any ongoing investigations or reviews being undertaken by his office."