WASHINGTON (CNN) -- A day after admitting to an extramarital affair, Nevada Sen. John Ensign has resigned his position in the Senate Republican leadership, Senate Minority Leader Mitch McConnell said in a statement.
Sen. John Ensign of Nevada is considered a rising star in the Republican Party.
Ensign was the head of the Republican Policy Committee, the fourth-ranking elected leadership position.
McConnell said Ensign has "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."
Ensign, 51, admitted Tuesday he had an extramarital affair with a woman who had worked for him. He would not identify the woman, but said she and her husband -- who also worked for Ensign -- had been "close friends."
"Last year I had an affair," the senator told reporters outside of his Las Vegas office. "I violated the vows of marriage. It's absolutely the worst thing I've done in my life."
Ensign said he knows "I have deeply hurt and disappointed my wife Darlene, my children, my family, friends, my staff and those who believed in me. And to all of them, especially my wife, I'm truly sorry."
Ensign's office also released a statement from his wife, which said, "Since we found out last year we have worked through the situation, and we have come to a reconciliation. This has been difficult on both families. With the help of our family and close friends our marriage has become stronger. I love my husband."
The affair between Ensign and the woman, a campaign staffer, lasted from December 2007 through August of 2008, according to Ensign spokesman Tory Mazzola.
The woman's husband was an official Senate staff member for the senator, Mazzola said. Neither remained in Ensign's employ as of May 2008.
Ensign is a veterinarian, and is considered a rising star within the Republican Party. He was first elected to the Senate in 2000 and comfortably won re-election in the midterm elections of 2006, when Democrats won back Congress. He is up for re-election in 2012.
CNN's Ted Barrett contributed to this report.