Updated

Three GOP congressmen introduced a resolution Friday calling for special counsel Robert Mueller to resign from the Russia collusion probe, citing his ties to the FBI and its role in controversies involving Russia.

Rep. Matt Gaetz, R-Fla., a member of the House Judiciary Committee, along with co-sponsors, Rep. Andy Biggs, R-Ariz., and Louie Gohmert, R-Texas, introduced the resolution on Friday.

“Evidence has emerged that the FBI withheld information from Congress and from the American people about Russian corruption of American uranium companies,” Gaetz said in a statement Friday. “A confidential U.S. witness, working in the Russian nuclear industry, revealed that Russia had deeply compromised an American uranium trucking firm through bribery and financial kickbacks.”

Gaetz was referring to Mueller’s supervision of a bribery probe involving a subsidiary of Russia’s Rosatom, which eventually got approval from the U.S. to buy a Canadian mining company, Uranium One, that controlled a swath of American uranium reserves. At the time of the probe, Deputy Attorney General Rod Rosenstein, who appointed Mueller as special counsel, was a U.S. attorney and Mueller was FBI director. Republicans want to know how that deal was approved despite the evidence gathered in the bribery probe.

MUELLER FACING NEW REPUBLICAN PRESSURE TO RESIGN IN RUSSIA PROBE

Gaetz also pointed to the FBI informant, whose gag order was lifted by the Justice Department last week, and is now able to provide information to Congress, free of the FBI’s nondisclosure agreement he signed when Mueller served as director.

“Although federal agents possessed this information in 2010, the Department of Justice continued investigating this “matter” for over four years. The FBI, led at the time by Robert Mueller, required the confidential witness to sign a non-disclosure agreement. When the witness attempted to contact Congress and federal courts about the bribery and corruption he saw, he was threatened with legal action,” Gaetz said in a statement. “By silencing him, Obama’s Justice Department and Mueller’s FBI knowingly kept Congress in the dark about Russia’s significant and illegal involvement with American uranium companies.”

Gaetz said that due to these “deeply troubling” events, Mueller’s “impartiality is hopelessly compromised.”

“He must step down immediately,” Gaetz said Friday.

Rep. Trent Franks, R-Ariz., has also called for Mueller’s resignation.

Senate Judiciary Committee Chairman Chuck Grassley, R-Iowa, has called for an independent special counsel to investigate the Obama-era Uranium One deal.

There are currently two pieces of legislation in the Senate, with bipartisan sponsorship, that would ensure a judicial check on the executive branch’s ability to remove a special counsel. Republican Sens. Lindsey Graham, R-S.C., and Thom Tillis, R-N.C., are behind the bills, along with Democratic senators.

The proposed resolution comes just days after Mueller’s team announced the first charges in their investigation into Russian meddling and potential collusion with Trump campaign officials in the 2016 presidential election.

Former Trump campaign chairman Paul Manafort and his associate Rick Gates were indicted on 12 counts by a federal grand jury as part of the probe. Both pleaded not guilty. And Former Trump foreign policy campaign volunteer George Papadopoulos entered a guilty plea on Monday after admittedly making false statements to the FBI.