Of course she has been excoriated by feminists for saying that much marital disharmony might be overcome if women just "put the canoe in the water" and start paddling, even if they don't feel like it. "Bettina Arndt rape cheerleader" was one furious blog response. "F--- you, Bettina Arndt," was another. Eva Cox of the Women's Electoral Lobby launched a counterattack, claiming that it's men's own fault they aren't getting enough sex, because they don't do their fair share of housework. "After an evening of organising kids, dinner, the shopping, the washing, the homework, etc, maybe [women] are too tired to want sex." It's an old excuse. As Arndt says, any time men complain about something, even in the anonymity of a sex therapist's book, feminists hit back with the housework furphy. The fact is, when you add up in-home and out-of-home duties, men work just as many hours as women, and sex has very little to do with it. The latest ABS social trends survey, released last week, found that women do almost twice as much housework as men - 33 hours and 45 minutes a week.

But while men might not do as much vacuuming and ironing, they spend a lot more time than women working outside the house in paid jobs - an average of 31 hours and 50 minutes a week, compared with women's 16 hours and 25 minutes. In other words, men and women do about the same amount of work in total - about 50 hours a week each. It's called division of labour and it has long been the negotiated settlement of marriage. Men have tried to up their share of housework - by 8 per cent - since 1992. But it doesn't seem to have increased their share of sex, judging by The Sex Diaries. In her chapter "Laundry Gets You Laid?", one of Arndt's diarists describes her husband as the "domestic God", yet their libidos are still worlds apart. Another diarist, Mary, 42, has put her husband on sex "starvation rations" until he does more housework.

But, she admitted: "[My husband] argues that even if I were a lady of leisure with a maid and housekeeper and no need to work … I still wouldn't be interested in sex. I deny deny and deny, but deep inside I have to admit there is a chance he might be right." Housework is just one of the excuses used by women to fend off their partner's advances. Only 10 per cent of Arndt's female diarists had higher sex drives than their partners and her book is full of the anguish of the other men, whose wives have just lost interest. Arndt said yesterday that female libido is so fragile it is easy to find excuses not to have sex. But desire is a decision. Women "have to make a decision to put sex back on the to-do list because if you allow these other things to swamp your sexual interest your relationship will be in real trouble". Of course, "resentment is a passion killer", and unequal share of household duties has long been high on a woman's list of resentments. "But it strikes me as being so unfair that women feel entitled to voice their complaints and demands of a relationship, yet a lot of men have at the absolute top of their wants and needs more sex and it's been totally ignored.

"How can we justify simply shutting up shop or forcing a man into a life spent grovelling for sex?" The picture Arndt gets from her male sex diarists is in large part a lament for love denied. They love their wives but desperately need the intimacy they used to have. They feel cheated. "I am totally at a loss as to what to do," writes Andrew, a 41-year-old diarist, married for six years, with two children. He and his wife used to have sex every day but are down to once every five or six months. "I do love her and I think she loves me but I cannot live like a monk. "What makes women think that halfway through the game they can change the rules to suit themselves and expect the male to take it?" Arndt is not suggesting women have sex against their will, but to heed new research that shows they may still enjoy sex even if they didn't crave it in the first place. Mismatched desire need not spell the end of a couple's sex life.

The other side of the equation is women's guilt at their own lower sex drive. Understanding that male and female sex drives are different was the key to rapprochement in the bedroom, she said. "It's all about walking in each other's shoes. Most of the women are upset that they don't want sex. It's not a deliberate thing … but we have to find a way around it if we have marriages lasting 40 years." Since the book was published, Arndt has been inundated with emails and messages from frustrated men. Loading But she has also touched a nerve with women. The day after Arndt appeared on the ABC's Lateline to promote her book, a friend told her that every woman in her tuckshop group had sex with their husbands.