CNN is reporting that presidential candidate Herman Cain will fight allegations of unwanted sexual advances from Phoenix.

He's scheduled a news conference for 3 p.m. Tuesday afternoon at the Scottsdale Plaza resort.

Sharon Bialek accused Cain publicly on Monday of touching her inappropriately in 1997.

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.