Republican presidential contender Herman Cain told his staff on today he was reassessing the future of his campaign after a woman accused him of having a 13-year affair, a senior adviser said.
Mr Cain, a former pizza executive who has already been hit by allegations of sexual harassment, has denied he had an affair with the woman.
He has nosedived in polls in recent weeks after he was hit by harassment allegations.
Until recently a front-runner among Republicans seeking to challenge President Barack Obama, Mr Cain had said he would stay in the race as long as his wife stood by him.
The woman, Ginger White, told a local Atlanta television station that the on-and-off affair began in the mid 1990s. She said he flew her to different locations for secret meetings. "It was pretty simple," Ms White told the Fox Network station in Atlanta. "It wasn't complicated. I was aware that he was married. And I was also aware I was involved in a very inappropriate situation, relationship."
Earlier charges of sexual harassment by four women, coupled with campaign gaffes, helped knock Mr Cain out of the top of the Republican presidential race, leaving a void that has now been filled by former House of Representatives Speaker Newt Gingrich.
Ms White said the two met at a presentation Mr Cain gave for the National Restaurant Association in Kentucky, and afterward the two had drinks. Mr Cain invited her back to his hotel, she said, and the relationship took off.
The woman provided cell phone bills showing calls to a number she said was Mr Cain's personal mobile phone. A reporter for the station called that number and reached Mr Cain, he said.
Reuters