Republican Sen. John Ensign of Nevada has stepped down from his leadership post one day after admitting he carried on an extramarital affair with a woman who was on his campaign staff.
Ensign conveyed his decision in a phone call with Senate Republican Leader Mitch McConnell, who said he had accepted the resignation.
Ensign was chairman of the Republican Policy Committee, the fourth-ranking spot in the leadership.
He remained away from the Capitol during the day, and aides declined to answer additional questions about the affair.
"He's accepted responsibility for his actions and apologized to his family and constituents. He offered, and I accepted, his resignation as chairman of the Policy Committee," Senate Republican Leader Mitch McConnell of Kentucky said in a statement Wednesday.
A timeline issued Tuesday said Ensign was involved in a "consensual affair" from December, 2007 through August, 2008. There has been no indication of why the senator decided to announce his infidelity when he did.
Ensign apologized Tuesday for the affair and said he remains "deeply committed" to his service in the U.S. Senate.
In Las Vegas on Tuesday, Ensign called the affair "absolutely the worst thing that I have ever done in my life," and said he and his wife sought counseling and reconciled.
He didn't name the staffer or her husband, and took no questions after issuing his statement.
He called the woman and her husband "close friends," and said that close relationship at a difficult time in his marriage "led me to my inappropriate behavior."
Ensign was first elected to the Senate in 2000.