He lopes across the stage and blinks at the 400 eager faces below. "Well," he says slowly in a voice that is pure Australian honey. "Whaddave we goddere?" He peers at the audience for a moment. "Hmm. Awrighdy!" A small giggle runs through the room. Three more minutes, and the giggle has grown to a roar of laughter.

Biddulph is not only a parenting expert, but also a pretty gifted comedian. He roams about the stage, acting out scenarios, pulling funny faces, waggling his immensely long arms, grinning hugely at his own jokes, judging his comic pauses to perfection. For two hours, barely five minutes go by without him cracking us up.

Biddulph's books have earned him a worldwide reputation as an expert on raising children, and, in particular, raising boys. He has sold more than two million copies and been translated into 17 languages. He is here for two weeks on the British leg of a world tour, lecturing and running workshops.

Despite the mellifluous voice and gentle demeanour, Biddulph is a man with a mission. His personal and professional crusade is no less than to save ordinary family life, which he sees as an endangered species in modern Western society. "Our culture doesn't want us to spend time with our children. It wants us out at work earning money. What I see in Britain is incredible pressure on everybody to be in the workforce. There are people who will have a fortnight's holiday in the Bahamas every year but not be able to spend Saturdays with their kids."

Biddulph is increasingly interested in how adults, not children, are behaving. "Seventy per cent of discipline problems with children stem from parents' hurry," he says. "There's no way that kids can be more relaxed than their parents. They are like the corks on the ocean of our lives. They bob along on our ups and downs. The real enemy of love is hurry." No hypocrite, Biddulph is retiring from public life this autumn, "to finish raising my family properly".

He is very protective of his own children, politely refusing to give their names or even ages. As his reputation has grown, he's shifted more and more of his work "off-shore', as he calls it, to enable them to be ordinary children, and he and his wife, Sharon, to be ordinary parents.

He spent the first nine years of his own childhood in Yorkshire, moving to Australia in 1963. As a boy he learnt to be tough, that parents love their children but wouldn't dream of telling them so, that words hurt a child's self-esteem as surely as blows hurt his body. As an adult, he's made a career of unlearning it all.

The theme of his work is relationships: between parents and children, children and parents, men and women. His big concern right now, however, is men. He points to the current high levels of depression, alcoholism and suicide. "Men's problems have been there ever since industrialisation, when they first got separated from family and community. But the advances women have made in the past 30 years as a result of feminism have highlighted men's impoverished situation."

Biddulph is by no means alone in worrying about this. The past 10 years have seen a rising tide of books on the difficulties of being masculine, such as the recent On Men: Masculinity in Crisis, by psychiatrist Anthony Clare. "Anthony Clare's a great guy," he says, "but he's still at the throwing-up-his-hands stage."

Biddulph himself has written two books on the subject of masculinity, Raising Boys and Manhood. In the first, he argued that the education system in the West is not geared to boys' needs and that this leads directly to many of the problems we see in young men today. The book caused such a storm in Australia that the government called him in for consultations.

Manhood is more concerned with why men so often come unstuck in their personal relationships, as fathers, sons, lovers and husbands.

One of Biddulph's big concerns is male sexuality, which he believes is so over-genitalised from adolescence that it undermines men's ability to feel alive in other parts of their bodies and minds. "The sex sell in this country is incredible. It's amazing that young British men can think straight. They're taught that they want one thing and they believe it." He believes the unhappiness men feel about their sexuality is behind the high divorce, suicide and alcoholism rates.

His seven-point action plan - "a kind of car manual for men's lives" - is designed to help men communicate more meaningfully with their wives, their families and, above all, themselves.

All of this is music to most women's ears, of course. But he insists his appeal is not only down to telling men what women have been trying to tell them for donkey's years. "I'm not blaming men and I'm not just saying, `spend more time with the kids'. I'm saying, `your role as a man is irreplaceable. There are things that only a man, only a dad can do'. This is politically incorrect, but I say it anyway."

On the brink of his (I suspect, temporary) retirement, Biddulph is optimistic. "Sometimes people seem to progress as a culture. It is as if we collectively cotton on to something and surge forward. It used to be routine to belt kids, but we no longer think that is OK." Such a shift is happening now, he believes, in terms of men and their relationships, and our attitudes to families, work and time.