Former African National Congress (ANC) MP Vytjie Mentor has alleged in a new book that President Jacob Zuma made inappropriate sexual advances on her while he was deputy president of the country.

She says she twice rejected him, once while she was a younger ANC member in the early 1990s, and then when she was chairperson of the ANC caucus in the mid-2000s.

"Zuma tried his luck with me on two occasions. I dealt with him and continued with my work. But he continued to prey on women," she told the Cape Town Press Club on Thursday.

Her new book No Holy Cows includes her experience of the extent of sexual harassment in the ruling party.

"So maybe the regret is, if I had exposed him better, a 'Kwezi' may not have happened," she said, referring to Zuma’s rape accuser, Fezekile Ntsukela Kuzwayo. He went on trial and was found not guilty in May 2006.

"But I cannot live with regret, so I'm doing this now to give courage to many women," she said.

Mentor alleges that, at a party conference in Durban Westville 25 years ago, Zuma made his first sexual advance while in a car. She said he introduced himself to her that evening, and invited her to his hotel room.

When she told him she had to look after her three-month-old baby, he told her he could arrange for a babysitter and that a car could be sent for her, she claims.

'I kept on moving away and he kept on'

The second time it happened in Zuma's office. Zuma was deputy president and head of political communication at the time.

She initially thought the meeting would take place in a board room or in her office, but Zuma asked for it to be changed to his office, she says. There were two guards outside his office. One remained at the door, the other invited her inside, she told the Press Club.

Zuma dismissed the guards, saying he was "surely not in danger from her". She and Zuma sat on separate couches, but he eventually he sat next to her.

He shifted his body closer and closer, and each time she moved further away. She eventually put her handbag between them, before leaving midway through the meeting.

One guard asked her what had happened when he saw her leave. "Go ask him," she replied.

"That is persistence. I kept on moving away and he kept on. If that is not persistence, I don't know what persistence is."

'I don't think I'm the only victim'

Mentor said she was speaking out now because "everything has its time".

"I'm speaking out because I'm encouraging others to speak out. I'm sure there are many other victims. I don't think I'm the only victim."

She said a member of the ANC caucus beat up a woman she knew in the Free State.

"If they choose to report things internally, you cannot coerce them to go public. I cannot say it's endemic in the ANC only, but I can for sure say it's endemic in society."

Silence about sexual harassment in an organisation merely allowed it to grow, she said.

"I don't think the ANC has done enough to arrest the culture of sexual harassment of women in its ranks. I also don't think the government and society have done enough in this country."

She said she intended to self-publish the book, as she would lose her "voice" if it was edited by a publisher. She wanted every South African to be able to read it.

Mentor said she expected a backlash from some of the people mentioned in the book, but this did not bother her.

"Those who want to go to court can go to court. I've been trying to take Zuma to court for a long time, so it will be nice to meet him in court."

Mentor has been an outspoken critic of the Gupta family. In her book, she cites other cases of sexual harassment and reveals her thoughts about state capture and the Marikana shooting.

Presidency spokesperson Dr Bongani Ngqulunga could not immediately be reached for comment.