Rep. Devin Nunes said Thursday he is stepping aside from the Russia investigation by the House intelligence committee because he is under investigation by the House Ethics Committee for allegedly disclosing intelligence without proper authorization.

"The charges are entirely false and politically motivated, and are being leveled just as the American people are beginning to learn the truth about the improper unmasking of the identities of U.S. citizens and other abuses of power," Nunes said in a statement, adding that the allegations against him are "baseless."

Nunes said in a hastily arranged press conference last month he had come into possession of classified information showing Trump transition team members were "incidentally collected" by U.S. intelligence agencies during their surveillance of foreign targets and improperly "unmasked." Nunes made his claim following a late-night trip to the White House where he reportedly met with senior administration officials who played a role in giving him classified information. (Nunes maintains they were not his original source.) Nunes was criticized for briefing the president—who is under investigation by his panel—before his own committee’s members, and Democrats on the panel quickly began to question the independence of the probe.

Rep. Mike Conaway, a Republican, will take Nunes's position as the leader of the committee’s investigation into Russia as the Ethics Committee begins its work. This responsibility will be shared with Reps. Trey Gowdy and Tom Rooney, who are other Republicans on the panel.

“I will continue to fulfill all my other responsibilities as Committee Chairman, and I am requesting to speak to the Ethics Committee at the earliest possible opportunity in order to expedite the dismissal of these false claims,” Nunes said in a statement Thursday.

The Ethics Committee is truly bipartisan, with an equal number of Democrats and Republicans. The 18(a) investigation, as it’s known, has subpoena power and may also look into what Nunes told Speaker Paul Ryan and President Donald Trump when he briefed them following his March 22 press conference.

"The committee notes that the mere fact that it is investigating these allegations, and publicly disclosing its review, does not itself indicate that any violation has occurred, or reflect any judgment on behalf of the Committee," it said in a statement.

Rule 18(a) is a procedural rule that the House Ethics Committee invokes to launch an investigation. It indicates that rather than create a subcommittee to look into the matter, it will be a staff-driven inquiry.

While Nunes blamed “leftwing” groups for the investigation, the 18(a) investigation suggests that the House Ethics Committee initiatives its investigation at its own accord, rather than from a referral through an outside complaint.

There is a very low bar for the House Ethics Committee to launch a probe into whether a lawmaker made an unauthorized disclosure of classified information. The way the arcane House rules are written, the House Ethics Committee requires an investigation if there is merely an allegation of classified information being spilled.

“The Committee on Ethics shall investigate any unauthorized disclosure of intelligence or intelligence-related information,” reads the rule—a command, rather than a suggestion.

The collapse of the House Intelligence Committee’s investigation into Russian meddling in the U.S. elections happened over the course of just fifteen days. Two weeks ago, Nunes held a press conference to announce that he had evidence of Trump’s transition team being swept up in foreign surveillance.

Nunes had not briefed Rep. Adam Schiff, his Democratic counterpart on the committee, before running to Ryan and Trump. That decision blew up an already strained committee, leading to recriminations from Democrats that Nunes was acting like a presidential pawn. The committee's downward spiral led to suspended hearings on the Russia probe, putting the onus on the Senate Intelligence Committee.

Nunes’s story also began to fall apart. First it was revealed that he had mysteriously vanished from his staff before his press conference. Then media outlets began to report that he had visited the White House before he held his press conference, followed by the revelation that his sources were White House staffers. It appeared that the White House had orchestrated a ‘leak’ to itself.

The committee's downward spiral led to suspended hearings on the Russia probe, putting the onus on the Senate Intelligence Committee to conduct a bipartisan review.

Schiff said Thursday morning Nunes's decision was in the "best interests of the investigation. I think it will allow us to have a fresh start for moving forward." The top Democrat on the committee said he looks forward to working with Rep. Conaway.

Following the announcement, Schiff told reporters he had heard the news in the SCIF, a secure area used to review classified information, and said that the mood among House Intelligence Committee members there was “somber.”

Democratic members of the committee commended Nunes’ decision and hoped that it would restore independence to the panel’s Russia investigation.

“It was the right call for Chairman Nunes to step aside from the Intelligence Committee's investigation into Russia's election interference,” Rep. Eric Swalwell said in a statement. “We now have a chance to reclaim our committee's independence, credibility, and ability to make progress.”

Speaker Ryan also said Nunes was right to step aside because it would be a "distraction" for the investigation into Russia's interference in the election and possible collusion with Trump's team. Ryan earlier expressed support for Nunes.

"He continues to have that trust, and I know he is eager to demonstrate to the Ethics Committee that he has followed all proper guidelines and laws," Ryan said in a statement. "In the meantime, it is clear that this process would be a distraction for the House Intelligence Committee’s investigation into Russian interference in our election. Chairman Nunes has offered to step aside as the lead Republican on this probe, and I fully support this decision."