House Intelligence Chairman Devin Nunes announced Thursday that he is temporarily stepping aside from the panel’s probe into Russian interference in last fall’s election and ties between President Donald Trump’s campaign team and Russian officials. The House Ethics Committee is investigating Nunes’ conduct.

The California Republican, a Trump supporter, has faced Democratic calls to relinquish his chairmanship over criticism that he could not lead an impartial investigation. His announcement said he would remain as chairman, but would allow GOP Reps. K. Michael Conaway of Texas, Trey Gowdy of South Carolina, and Tom Rooney of Florida to temporarily take control of the investigation.

“Several left-wing activist groups have filed accusations against me with the Office of Congressional Ethics,” Nunes said in a statement. “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.”

“Despite the baselessness of the charges, I believe it is in the best interests of the House Intelligence Committee and the Congress for me to have Representative Mike Conaway, with assistance from Representatives Trey Gowdy and Tom Rooney, temporarily take charge of the committee’s Russia investigation while the House Ethics Committee looks into this matter,” Nunes said. “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.”

The eight-term Republican’s handling of information that Trump officials may have been swept up in surveillance led to calls from top Democrats, including the Intelligence ranking member Adam B. Schiff of California, for him to step aside.