NEW YORK -- Speaking in a halting voice, a Chicago-area woman accused Republican presidential contender Herman Cain on Monday of making an unwanted sexual advance against her more than a decade ago, saying she wanted to provide "a face and a voice" to support other accusers who have so far remained anonymous.
"Come clean," Sharon Bialek challenged Cain, demanding he confess to any inappropriate behavior with her or other women.
Cain's campaign instantly issued a denial. "All allegations of harassment against Mr. Cain are completely false," it said.
Bialek's appearance at a news conference marked a new and -- for Cain -- dangerous turn in a controversy that he had been trying to lay to rest.
She described an evening in mid-July 1997 when she had dinner in Washington, D.C., with Cain, whom she had contacted in hopes he could help her find a job. The two were in a car for what she thought was a ride to an office building.
"Instead of going into the offices he suddenly reached over and he put his hand on my leg, under my skirt toward my genitals," she said.
"He also pushed my head toward his crotch," she added.
She said she told Cain to stop, adding that he did.
Bialek said she did not file a workplace complaint against Cain at the time because she was not employed.
She said she informed both her boyfriend, an unidentified pediatrician, and a longtime male friend.
Bialek appeared at a news conference alongside Gloria Allred, an attorney known for sexual harassment cases.
As if to blunt any attacks on her client's motives, the attorney described Bialek as a registered Republican, and a woman with a long and successful work history.
Bialek was employed for parts of 1996 and 1997 at the Educational Foundation of the National Restaurant Association, an industry trade group that Cain headed at the time. She said she first met him at an organization convention, interacting with him several times over the course of a few days.
She was fired from her job, and her boyfriend suggested she contact Cain in hopes he could help her find employment.
That led some time later -- Bialek said mid-July 1997 -- to a trip to Washington, where Cain upgraded her hotel room to a suite, and the unwanted sexual advance took place after they had gone to dinner.
"I want you Mr. Cain to come clean," she said. "Just admit what you did. Admit you were inappropriate to people."
She added: "Mr. Cain, I implore you: Make this right so that you and the country can move forward and focus on the real issues at hand."
The denial from Cain's campaign was as unequivocal as the allegation.
"Just as the country finally begins to refocus on our crippling $15 trillion national debt and the unacceptably high unemployment rate, now activist celebrity lawyer Gloria Allred is bringing forth more false accusations against the character of Republican front-runner Herman Cain," it said.
"Mr. Cain has never harassed anyone."
Cain spent much of last week denying allegations by three women who remained anonymous. By the weekend, he said he would no longer respond to questions about allegations of sexual harassment.
"Don't even go there," he chastised some reporters who sought to question him Saturday night after a joint campaign appearance with former House Speaker Newt Gingrich.
Some Republicans, including presidential rival Jon Huntsman and Mississippi Gov. Haley Barbour, have urged Cain to respond more fully to the charges, and Bialek's appearance in New York was likely to add to the clamor.
Cain had an appearance scheduled for later in the day on the Jimmy Kimmel show, his only public event of the day.
Before Bialek stepped to the microphone, the allegations involved two women who had worked at the National Restaurant Association, both of whom filed sexual harassment complaints.
A third woman told The Associated Press last week that she considered filing a workplace complaint against Cain over what she deemed sexually suggestive remarks and gestures that included a private invitation to his corporate apartment.
A former pollster for the restaurant association has said he witnessed yet another episode involving a fourth woman. It was unclear whether that woman is Allred's client.
Allred has represented several high-profile clients, including Amber Frey, a witness against convicted California killer Scott Peterson. Allred also represented a woman whom news reports accused of having an affair with golfer Tiger Woods.
"I consider sexual harassment the No. 1 problem in the workplace," she told the AP in an interview last week. "It denies equal opportunity in the workforce. If (women) don't protest it, they'll have to continue to suffer."