Shortly before a federal grand jury reportedly filed the first charges in special counsel Robert Mueller’s investigation into Russian meddling in the 2016 election, conservatives were renewing their calls for the attorney to resign.

Mueller, who is leading the Justice Department’s investigation as special prosecutor, is a former FBI director, which critics say creates a conflict of interest in the case.

He also previously worked with former FBI director James Comey, who President Donald Trump fired in May amid the agency’s investigation into Russian interference. David N. Kelley, Comey’s attorney, has disputed Trump’s claim that Comey and Mueller were close friends, maintaining that the pair were “friends in the sense that co-workers are friends.”

The GOP has long complained about Mueller’s supposed lack of objectivity. But this week, demands urging him to quit escalated in the wake of reports that the Democratic National Convention and the Hillary Clinton campaign funded opposition research that turned up a secret dossier on Trump and his alleged Russia ties.

On Thursday the editorial board of the Wall Street Journal ― a crown jewel in the media empire of Rupert Murdoch, a close Trump ally — went after Mueller as well. It wrote that the dossier news raises the question of whether the document helped fuel the FBI’s probe into Trump’s campaign. Since the dossier attributes allegations to “Kremlin-connected sources,” the board argues that would mean the FBI could have been essentially acting on “disinformation” provided by Russia. And if there were a need to investigate the FBI’s actions, that would make Mueller’s FBI ties a major conflict of interest.

“The federal code could not be clearer – Mueller is compromised by his apparent conflict of interest in being close with James Comey,” Rep. Trent Franks (R-Ariz) said in a statement to Fox News on Friday. “The appearance of a conflict is enough to put Mueller in violation of the code.”

Friday morning, New Jersey Gov. Chris Christie (R) said on “Fox and Friends” that “somebody with Bob Mueller’s integrity” should “step aside.”

Trump has also tweeted that the FBI may have helped pay for the dossier directly, though there’s no apparent evidence this is true.

Meanwhile, journalist Carl Bernstein — best known for his work with Bob Woodward reporting on the Watergate scandal —is accusing Trump of trying to “sabotage” Mueller’s investigation.

“The Russians interfered in our electoral process, and there is an investigation into whether Donald Trump and those around him had foreknowledge of those attempts, and what their relationships were with Russians, business relationships that might have made them vulnerable to Russian objectives,” Bernstein said on Don Lemon’s “CNN Tonight” on Friday. “That’s what Mueller is investigating. And he ought to be able to have the opportunity, without the president of the United States trying to sabotage his investigations, to follow through.”