* Cain says will talk face to face with wife on Friday
* Claims 'groundswell of support' since affair allegation
* Rallies supporters at New Hampshire headquarters
(Recasts with comments from New Hampshire campaign headquarters, previous DAYTON, changes byline)
By Jason McLure
MANCHESTER, N.H., Nov 30 (Reuters) - Republican presidential hopeful Herman Cain, battling allegations of infidelity, said on Wednesday he would decide whether to continue his campaign after a face-to-face talk with his wife.
While vowing not to end his candidacy over accusations he had a long-term affair, the former pizza company executive said a frank talk on Friday with Gloria, his wife of 43 years, would be a big part of a "reassessment" of his White House bid.
"I have talked to my wife many times since Monday about this situation. I have not talked to her about this face to face," Cain told reporters after rallying supporters at his New Hampshire campaign headquarters in Manchester.
Once a frontrunner in the race to challenge President Barack Obama in 2012, Cain called recent reports that he had an affair with an Atlanta-area woman "character assassination" and "conviction in the court of public opinion."
He has said he will decide within "several days" whether to stay in the race.
Earlier, at rallies in Ohio, Cain said most of his supporters were sticking with him despite the latest controversy, which came amid accusations he had sexually harassed a number of women. He accused his critics of trying to bring down his upstart White House bid.
"They want you to believe that with enough character assassination on me that I will drop out," a defiant Cain said in Dayton, drawing a chorus of "boos" from the crowd.
Cain, who has denied the affair and harassment accusations, did not rule out other potential accusers emerging. "My career was in business for over 40 years. I have worked with thousands of people. I can't possibly say that someone wont trump up another allegation. It just goes with the territory."
Cain, 65, denies having an affair with Ginger White, who says their 13-year, on-and-off relationship began in the mid-1990s. He said he thought she was a friend and he was simply giving her financial assistance.
The candidate, who led the Republican race barely more than a month ago, has nosedived in polls after being hit by sexual harassment charges from four women and stumbling recently on the campaign trail.
He raised alarm among conservatives with confusing comments about abortion and badly fumbled a question on Libya policy.
A Reuters/Ipsos poll found Cain's departure would do little to change the race, with his depleted support carved up among the field. Top rivals Mitt Romney and Newt Gingrich would gain the most, with bumps of about 3 percentage points each, while other contenders would pick up slightly less.
The allegation of an affair came five weeks before Iowa kicks off the state nominating contests, giving Cain little time to resurrect his once high-flying campaign.
But he said on Wednesday there was "a groundswell of support" for his candidacy after White's claims. The new disclosures have not sparked widespread defections.
Some of those in Ohio who came to hear Cain speak said they were willing to give the candidate a chance.
"I am more convinced than I ever was. I believed him and I am going to donate to him and vote for him," said Christine Bolte, 46, a substitute teacher who is working as a cashier at Wal-Mart to help pay her bills.
In New Hampshire, which will hold a closely-watched primary contest in January, Cain said fundraising slumped the day the Ginger White scandal broke, but had started to bounce.
"As the week has gone on and this woman who has made these accusations has started to contradict herself, our fundraising has gone up," he said.
White told ABC's "Good Morning America" program that she remained in contact with Cain until last week.
"I've received gifts and money for the last 2-1/2 years, consistently," White said, adding Cain also took her on several trips. But she said he sought nothing in return.
"This was not sex for cash," White said.
ABC said White's phone records for October and November show numerous text exchanges with Cain, including daily contact in early November as reports emerged of sexual harassment allegations from other women.
(Reporting by Jason McLure in Manchester and Eric Johnson in Dayton, Ohio; Writing by John Whitesides and Ros Krasny; Editing by Mohammad Zargham, Philip Barbara and Paul Simao)