Caroline Green, who was married to the anti-gay Christian extremist for 26 years, says she has come forward now because “the people who support him financially and morally should know what he is really like”.
Mr Green, 60, who was recently interviewed by the BBC over his views on Elton John becoming a father, has approved of the death penalty for gays and lesbians.
He leads Christian Voice, which is a small protest group of around 300 members. The group rails against violence, abortion, immorality and drugs, although it reserves a special venom for homosexuality.
But Mrs Green, 59, said that those who donate money to Christian Voice should know the “truth” about her ex-husband.
She told the Mail on Sunday that he had beaten her and her children, “brainwashed” them and forced them to live in a dilapidated caravan in remote Wales to protect them from the “evil” of urban life.
Mrs Green described the incident which prompted her to leave him, recalling how he made a list of her failings as a wife and then beat her until she bled with a piece of wood.
She said: “He even framed our marriage vows — he always put particular emphasis on my promise to obey him — and hung them over our bed. He believed there was no such thing as marital rape and for years I’d been reluctant to have sex with him, but he said it was my duty and was angry if I refused him.
“But the beating was the last straw. It convinced me I had to divorce him.”
She also said that he had beaten their eldest and middle sons with belts and broomsticks.
She added: “It was almost like living in a cult. We were all subjugated to his will and cowed by him. Over the years he belittled us and made us feel worthless.
“Whenever I watch him on TV spouting verses from the Bible, or see him quoted in a newspaper, it turns my stomach. I’ve decided to tell the truth about him now because the people who support him financially and morally should know what he is really like.”
Mrs Green now lives in a small home in west Wales with one of her sons and her god-daughter Emily, who used to work for Mr Green.
He has since married a Kenyan woman 25 years his junior and declined to comment to the Mail on Sunday.