(CNN) -- Former U.S. senator and Democratic presidential hopeful John Edwards admitted Friday to an extramarital affair. He denied being the father of the woman's child, as had been alleged in tabloid reports.
"In 2006, I made a serious error in judgment and conducted myself in a way that was disloyal to my family and to my core beliefs," he said in a written statement. "I recognized my mistake and I told my wife that I had a liaison with another woman, and I asked for her forgiveness."
In an interview set to air Friday night on ABC's "Nightline," Edwards acknowledged the affair with 42-year-old Rielle Hunter, which began after she was hired to make documentary videos for his campaign, ABC said.
"You cannot beat me up more than I have already beaten up myself. I have been stripped bare and will now work with everything I have to help my family and others who need my help," he added in the statement.
He said that he has not taken a paternity test but that the timing of the affair rules out the possibility that he could be her baby girl's father.
Andrew Young, a former Edwards campaign aide who is married, has publicly said he fathered the child. The Washington Post reported Friday that Hunter acknowledged Young as the father.
When the tabloid the National Enquirer first reported the affair in October, Edwards flatly denied it, calling the claims "false" and "ridiculous."
Contacted through a former aide by CNN on Thursday, Edwards had refused to comment on the reports. He also dodged reporters at a recent event in Washington.
In a July 24 appearance in New Orleans, Louisiana, he would not answer a reporter's question about whether he had provided financial support to Hunter or Young.
"I have no idea what you're asking about," Edwards said. "I have responded to, consistently, to these tabloid allegations by saying I don't respond to these lies."
Edwards, 55, of North Carolina, told ABC that his wife, Elizabeth, and other family members have known about the affair since 2006.
Edwards, the vice presidential candidate during Sen. John Kerry's 2004 presidential bid, had been mentioned as a potential running mate for Sen. Barack Obama, the presumptive Democratic nominee this year, and as a possible attorney general or other high-ranking appointee if Obama wins the November election.
But Don Fowler, a former Democratic Party chairman, said this week that Edwards might be forfeiting a major role at the party's upcoming convention in Denver -- or in a future Democratic administration -- unless he cleared the air.
"I think the longer these allegations go unanswered and unresponded to, the more difficult it is for the people producing the convention to give him a prominent spot," Fowler said.
Fowler, of South Carolina, served as Democratic chairman from 1995 to 1997 and will be a party superdelegate at the Denver convention in late August. He said he had no input into whether Edwards addresses the convention, "but I would expect that he would not speak or have any role at the convention unless this is cleared up."
Speaking in support of Obama in Las Vegas, Nevada, on Friday, Edwards' former rival Sen. Hillary Clinton responded briefly to a reporter's question about what, if any, impact the revelation of the affair would have on Democrats.
"My thoughts and prayer are with the Edwards family today," she said. "That's all I have to say."
While the National Enquirer's claims about the affair were months old, they were revived July 22 when the tabloid reported it had confronted Edwards at a Beverly Hills, California, hotel after receiving a tip he was meeting Hunter and her daughter there.
A former Edwards campaign staffer on Friday would only confirm that Edwards did the ABC interview, saying he wanted to speak for himself, but declined to offer more detail. The same person said there was no word of a statement from Elizabeth Edwards.
Edwards told ABC that his wife's widely reported cancer was in remission when the affair began.
According to federal election records, the Edwards campaign paid Hunter's production company roughly $114,000 in 2006 and 2007 for "Website/Internet services."
The former North Carolina senator announced in January that he was dropping out of the 2008 Democratic presidential race.
"It is time for me to step aside so that history can blaze its path," he said in New Orleans.
With his wife and children at his side, Edwards said he couldn't predict "who will take the final steps to 1600 Pennsylvania Avenue," but he said it would be a Democrat.
Edwards endorsed Sen. Barack Obama on May 14 during a rally in Grand Rapids, Michigan.
He trailed Clinton and Obama in the early contests. He came in third in key races in New Hampshire and South Carolina.
Edwards had campaigned on the message that he was standing up for the little guy, the people who are not traditionally given a voice in Washington, and that he would do more to fight special interests.
After dropping out of the race, Edwards asked Clinton and Obama to make poverty a central issue in the general election and a future Democratic administration, something both agreed to do.
Edwards is a South Carolina native with an undergraduate degree from North Carolina State University and law degree from the University of North Carolina.
Before entering politics, winning a Senate seat from North Carolina in 1998, Edwards was a lawyer representing families "being victimized by powerful interests" and gaining "a national reputation as a forceful and tireless champion for regular, hard-working people," according to his campaign Web site.