ATLANTA — Republican presidential hopeful Herman Cain told supporters Saturday that he is suspending his presidential campaign, which has become hobbled in recent weeks by allegations of sexual harassment and an Atlanta woman’s claim that they carried on a 13-year affair.

While he will still be able to raise and spend campaign funds because he did not officially drop out, his White House bid is effectively over.

Cain said he came to the decision after assessing the impact that the allegations were having on his wife, his family and his supporters.

He repeatedly called the allegations “false and untrue,” and added that “the (media) spin hurts. “

Even as he stepped aside under the weight of the allegations that have dogged him, Cain said that he was at “peace with my God” and “peace with my wife.”

“I am not going to be silenced and I will not go away,” Cain said, announcing what he called his Plan B: A website, TheCainSolutions.com, through which he will continue to advocate for his platform.

His catchy “9-9-9” economic plan is not going anywhere, he said.

“Your support has been unwavering and undying,” Cain told his supporters.

He will endorse another of the Republican presidential hopefuls soon, he said.

Some of the other candidates were quick to react.

“Herman Cain provided an important voice to this process,” Minnesota Rep. Michele Bachmann said in a statement. “His ideas and energy generated tremendous enthusiasm for the conservative movement at a time it was so desperately needed to restore confidence in our country.”

Former Utah Gov. Jon Huntsman said Cain brought “a unique and valuable voice to the debate over how to reform our country’s uncompetitive tax code and turn around the economy. I understand his decision and wish him and his family the best.”

Cain’s announcement came a month before the Iowa caucuses, the first formal test of the primary season, scheduled for January 3.

Recently, Cain acknowledged that Ginger White’s allegations of an affair have led to a drop in campaign contributions, and a Des Moines Register poll showed his support among likely Republican Iowa caucus-goers has fallen to 8 percent, down from 23 percent in October. The poll has a sampling error of plus or minus 4.9 points, the newspaper said.

Respondents said they were most concerned that Cain does not understand important issues, but said the allegations against him contribute to their concern, the newspaper said.

This week, White told the news media that she and Cain engaged in an on-and-off affair for more than 13 years. She described the affair as “very casual.”

Two women — Sharon Bialek and Karen Kraushaar — previously accused Cain of sexually harassing them in the 1990s while he was head of the National Restaurant Association. Two other women also have said Cain sexually harassed them while they worked at the association, but they have declined to be identified.

Cain told the Union Leader that he repeatedly gave White money to help her with “month-to-month bills and expenses.” But he denied the relationship was sexual, as White contends. He said the two were friends.

“I send checks to a lot of people; I help a lot of people,” Cain told Fox News on Thursday. “That in itself is not proof. So the other allegation in terms of it being a 13-year physical relationship, that is her words against my word.”

In the interview, Cain said his wife, Gloria Cain, knew nothing about White nor his financial support for her until the mother of two came forward last week.

“My wife now knows,” he told the newspaper. “My wife and I have talked about it, and I have explained it to her. My wife understands that I’m a soft-hearted, giving person.”

Cain told staffers this week he was reassessing his campaign in the wake of White’s allegation of an affair, and he acknowledged to reporters Wednesday that her account had led to a drop in contributions to his campaign.

He said in an interview with the Union Leader on Thursday that his wife’s feelings, as well as the reaction from supporters and donors, would be important factors in deciding whether he will stay the race.

Cain told the newspaper he would drop out of the race if his wife asked him to, but quickly added that she wouldn’t.

Though Gloria Cain rarely makes public appearances or statements, she told Fox News last month that she believed the sexual harassment allegations were “unfounded.”

On Thursday, White described her relationship with Cain to MSNBC as a casual sexual affair, and told ABC’s “Good Morning America” that Cain gave her money and gifts for more than two years.

Cain acknowledged helping White financially, but has denied their relationship was sexual.

“She was out of work and had trouble paying her bills, and I had known her as a friend,” Cain told the Union Leader. “She wasn’t the only friend who I had helped in these tough economic times, and so her messages to me were relating to ‘need money for rent’ or whatever the case may be. I don’t remember all the specifics.”

Asked by the newspaper about reports of text messages he had exchanged with White, Cain confirmed that the woman had sent him about 70 such messages between Oct. 22 and Nov. 18, including some “asking for financial assistance.”

Cain’s attorney, Lin Wood, told CNN’s “Piers Morgan Tonight” on Thursday that White has provided no proof of an affair or associated financial receipts.

He said that his client has been a victim of unproven allegations and that the news media should be asking tough questions of White, whom Cain described in a fund-raising letter as “troubled.”

White said on “Good Morning America” that she had not saved receipts and notes throughout the affair because she never planned to make the relationship public. She said it was “very disappointing that he would call me troubled.”

While the controversy raged in the media, Cain’s campaign continued; the campaign sent an email message Friday asking for moral and financial support.

“I am inviting you to share your voice with me, my family and staff, and the nation,” Cain said in the message. “In short, I need to know that you are behind me 100%. In today’s political environment, the only way we can gauge true support is by the willingness of our supporters to invest in this effort.”

On Thursday, a campaign spokeswoman said Cain’s chief of staff met with the campaign’s four-person Iowa team to emphasize that the election drive was moving forward.

“Mark Block, Herman Cain’s chief of staff and chief operating officer, just left a meeting at the Iowa headquarters with all four Iowa staffers,” said a statement by Lisa Lockwood, the communications director of Friends of Herman Cain’s Iowa staff. “The emphatic message is that the campaign is full steam ahead. Herman Cain is in it to win it. He always has been and that has not changed.”