Republican U.S. Sen. Ron Johnson stood by his declaration that Robert S. Mueller III should resign, even as the first indictments were handed down Monday in the probe into Russian interference in the presidential election led by the special counsel.

Ben Voelkel, a Johnson spokesman, told the Milwaukee Journal Sentinel: "Day to day developments don’t change the senator’s view that a special counsel was appointed far too early in this process."

"Nor do they affect his overall concern that this investigation cannot tolerate even the appearance of a conflict of interest. Mr. Mueller is simply too close to James Comey and the FBI as questions continue to surface about their roles in matters the special counsel is investigating," Voelkel said.

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Mueller was appointed special counsel for the Russia investigation after President Trump fired Comey as FBI director.

On Friday, Johnson told the Racine Journal Times editorial board that Mueller "should resign" and that the special counsel's investigation was impeding Congressional investigations into Russian influence on the 2016 election.

“I take the position that we shouldn’t have a special counsel at this time. We should let the (congressional) committees do their work," Johnson told the editorial board.

The Journal Times reported that "Johnson said Mueller should resign because of the FBI’s handling of Hillary Clinton’s private email server along with recent information regarding sales of U.S. uranium while Mueller was FBI director."

On Monday, three former campaign officials for President Donald Trump were charged in the Russia probe.