WASHINGTON (Reuters) – Three Republican U.S. lawmakers called on Friday for Robert Mueller to resign as special counsel investigating Russia and the 2016 U.S. election, the latest in a series of conservatives’ criticisms of the FBI and Justice Department during the probe of how Moscow may have influenced the campaign.

Representatives Matt Gaetz, Andy Biggs and Louis Gohmert accused Mueller of a conflict of interest because he was director of the Federal Bureau of Investigation when former President Barack Obama’s administration approved an agreement allowing a Russian company to buy a Canadian company that owned 20 percent of U.S. uranium supplies.

President Donald Trump’s fellow Republicans have been calling for an investigation into the Uranium One deal, amid news of Mueller’s first indictments of Trump associates as the special counsel investigates allegations that the Trump campaign colluded with Moscow.

Moscow denies any effort to influence the election, and Trump has dismissed the investigation as a “witch hunt.”

On Monday, the day the indictments became public, White House Chief of Staff John Kelly said a special counsel should be appointed to investigate Democrats over the uranium deal.

Another group of Republican lawmakers, including House of Representatives Judiciary Committee Chairman Bob Goodlatte launched an investigation last week to examine issues including the role of former Secretary of State Hillary Clinton, Trump’s 2016 opponent, in the uranium deal.

Democrats have dismissed the Republicans’ activities as a partisan effort to distract from Mueller’s probe and from efforts to ensure that a foreign government, Moscow, does not influence future U.S. elections.

Gaetz, Biggs and Gohmert are all members of the House Judiciary Committee, which has oversight over the FBI and Department of Justice.

Gaetz has called for investigations of issues related to Clinton previously, including accusing former FBI Director James Comey of colluding with Mueller on the FBI’s investigation of Clinton’s emails.