Incoming Utah Republican Sen. Mitt Romney said Wednesday that it was critical for special counsel Robert Mueller to be allowed to finish his federal Russia probe as incoming acting Attorney General Matthew Whitaker takes the reins of the Justice Department.

Former Attorney General Jeff Sessions tendered his resignation to President Trump Wednesday, one day after the 2018 midterm elections, bringing to an end a yearlong feud between the pair sparked by Sessions' recusal from overseeing Mueller's inquiry.

"I want to thank Jeff Sessions for his service to our country as Attorney General," Romney tweeted. "Under Acting Attorney General Matthew Whitaker, it is imperative that the important work of the Justice Department continues, and that the Mueller investigation proceeds to its conclusion unimpeded."



I want to thank Jeff Sessions for his service to our country as Attorney General. Under Acting Attorney General Matthew Whitaker, it is imperative that the important work of the Justice Department continues, and that the Mueller investigation proceeds to its conclusion unimpeded. — Mitt Romney (@MittRomney) November 7, 2018



Romney's message could be setting the tone for how the 2012 GOP presidential nominee wants to use his new position as a senator as another check on the Trump administration.

The former Massachusetts governor's comments come on the heels of similar remarks by his new colleague, Sen. Susan Collins, R-Maine. Collins on Wednesday expressed her anxiety over how the Justice Department's change in management would affect Mueller's inquiry.

"I’m concerned Rod Rosenstein will no longer be overseeing the probe," she wrote. "Special Counsel Mueller must be allowed to complete his work without interference—regardless of who is AG."



It is imperative that the Administration not impede the Mueller investigation. I’m concerned Rod Rosenstein will no longer be overseeing the probe. Special Counsel Mueller must be allowed to complete his work without interference—regardless of who is AG. — Sen. Susan Collins (@SenatorCollins) November 7, 2018



Sen. Jeff Flake, R-Ariz., who is retiring from Congress at the end of his term in January, also weighed in on the Trump Cabinet reshuffle. Flake urged Senate Majority Leader Mitch McConnell, R-Ky., Wednesday to introduce a bill seeking to "safeguard" Mueller until he wraps up his work looking into the Trump campaign and its connections with Russia.

Mueller is additionally examining whether the president obstructed justice when he fired then-FBI Director James Comey as Comey was leading the bureau's own investigation into links between Trump's camp and the Kremlin ahead of the 2016 presidential election.



Earlier this year, we passed S.2644, the Special Counsel Independence and Integrity Act, out of the Senate Judiciary Committee. The bill would safeguard Robert Mueller’s investigation. Leader McConnell should bring the bill to the Senate floor as soon as possible — Jeff Flake (@JeffFlake) November 7, 2018



Whitaker, Sessions' old chief of staff, has been critical of Mueller, writing in an op-ed last year that Mueller's team had exceeded its scope and should be limited.