Republican presidential hopeful Herman Cain has told a late-night TV host that there's no truth to the latest sexual allegations against him.

Cain plans a news conference later today to confront accusations from Sharon Bialek, who held her own news conference yesterday.

Cain appeared last night on "Jimmy Kimmel Live."

  • Click here for more video from the Jimmy Kimmel interview.

Bialek, meanwhile, says she has "nothing to gain" by coming forward. She tells CBS's "The Early Show" she's standing by her assertion that Cain made an inappropriate sexual advance toward her at a time when she was seeking his help in finding a job.

Asked about Cain's characterization of her charges as a "total fabrication," Bialeck stood her ground. She said she went public because "I wanted to give him a platform to come clean, to tell the truth."

Cain will hold a press conference in Phoenix on Tuesday afternoon to address the allegations.