Washington (CNN)Republican Sen. Chuck Grassley said Thursday he will block two of President Donald Trump's nominees from moving forward in the confirmation process until the administration provides "adequate reasons" for firing the inspectors general of the intelligence community and State Department.
The move marks an escalation by Grassley after White House counsel Pat Cipollone chose not to explain why Trump had removed the two inspectors general last month, instead emphasizing the President's legal authority to do so.
Last month's letter from Cipollone, which Grassley swiftly blasted as having "failed to address" the congressional requirement that there "ought to be a good reason" for such dismissals, came in response to the Iowa senator's request that Trump explain why they had been ousted.
Now, the Iowa Republican says he will refuse to allow two of Trump's nominees to advance unless the White House provides details about why ICIG Michael Atkinson and State Department IG Steve Linick were removed earlier this year.
"Grassley will not consider the nomination of Christopher C. Miller to be the director of the National Counterterrorism Center until the White House explains why Intelligence Community Inspector General Michael Atkinson was terminated," his office said in a statement Thursday.
He "also will not consider the nomination of Marshall Billingslea to be the undersecretary for arms control and international security at the State Department until sufficient reasons are provided for the termination of State Department Inspector General Steve Linick," the statement said.
Grassley, the chamber's most senior Republican who has been a longtime defender of whistleblowers and government oversight, has broken with Trump on the topic several times during his presidency.
The President had announced his intent to remove Linick last month -- a move that drew immediate condemnation from top Democrats, who accused Trump of engaging in a pattern of retaliation against public servants charged with oversight of his administration.
And Linick's removal came after Trump's April ouster of Atkinson, who had told Congress about the whistleblower complaint that led to Trump's impeachment.
"Though the Constitution gives the president the authority to manage executive branch personnel, Congress has made it clear that should the president find reason to fire an inspector general, there ought to be a good reason for it," Grassley said Thursday.
"The White House's response failed to address this requirement, which Congress clearly stated in statute and accompanying reports. I don't dispute the President's authority under the Constitution, but without sufficient explanation, the American people will be left speculating whether political or self-interests are to blame. That's not good for the presidency or government accountability," he added.