A fourth woman accusing Herman Cain of sexual harassment during his time at the National Restaurant Assn. plans to go public with her allegations at a news conference Monday in New York.

The woman is represented by powerhouse Los Angeles attorney Gloria Allred. Allred had a similar news conference earlier this year on behalf of one of the women who was enmeshed in the Twitter scandal that brought down New York Rep. Anthony Weiner.

Allred’s office said the woman “is not one of the three women who have previously been reported to have alleged sexual harassment by the Republican presidential candidate ” and that she will be “the first to give her name and to speak out about details of what she alleges occurred between her and Cain.”

Two woman reportedly complained about Cain’s conduct during his time as head of the restaurant association in Washington but have not revealed their identities. A third considered bringing a complaint but did not, the Associated Press reported last week.

The latest accuser surfaces at a time when Cain and his campaign are desperately -- and perhaps now futilely -- trying to change the subject. Cain grew testy with reporters after a campaign event with former House Speaker and fellow GOP presidential candidate Newt Gingrich over the weekend, refusing to answer questions about the allegations. His campaign manager has been sending out copies of the Society of Professional Journalists’ ethics code in a bid to deter reporters from bringing them up.

And now there are some signs that the scandal is taking a political toll on Cain. An Ipsos/Reuters poll conducted online at the end of last week showed Cain’s favorability rating among Republicans dropping 9 points, from 66% to 57%, and his rating among all voters dropping from 37% to 32%. Perhaps more worrisome for Cain was that a full 80% of respondents said they knew about the harassment allegations. One in three Republicans said the accusations made them view Cain less favorably.

Allred's news conference is scheduled for 1:30 p.m. EST.