Natasha Walter is slim, pretty and 30. Her full lips and wide, generous mouth are of the kind that don't need lipstick. Her nails are long and painted liver-red, as popularised by Uma Thurman in Pulp Fiction. Beneath modish pencil-slim trousers, feet tucked into high-heeled shoes, her legs are probably hairfree.

Is this relevant? Some people think so. Because Walter is also a feminist, author of The New Feminism published later this month, a serious, meticulously researched look at the achievements of feminism and what remains to be done. A very broadsheet agenda. Yet headline writers and reviewers shamelessly proclaim her in tabloid terms as a "lipstick feminist". All very irritating, she sighs, as we sip tea at London's Groucho Club, given that one of her aims in writing The New Feminism was to counter the confessional feminism offered up by Naomi Wolf, Nancy Friday and even Camille Paglia, emanating from the States, which, she believes, is both alien and alienating to contemporary non-American women.

"I don't want to junk all these feminist writers that have come before. But young women now look around them and say, what is British feminism? There is something very real going on in their lives and it hasn't been brought out clearly enough in the media what that is. One of the reasons is that feminism at the moment is too much associated with women delving into their personal lives and talking about their bodies, their sexuality, their clothes, rather than going out and talking about those things I think are important, which are those issues about women's relative poverty, women's abuse."

But boys will be boys, and the extract chosen by the supposedly feminist-friendly Observer for its serialisation last Sunday was, of course, the chapter on clothes, make-up and how fashion is fun and not the sole domain of women. (Headline, "The feminine feminists: We'll wear lipstick and Wonderbras. Whether men like it or not".)

"First the photographer said: `Can I take a picture of you next to your wardrobe, holding your clothes?' And I said `No'. Then he said: `Can I take a photograph of you putting on your lipstick?' And I said `No'. And I said: `Look, it isn't a first person piece. It's about what's going on in Britain. I want to be seen as an author. Not as someone who's writing about themselves."' However, as a front line journalist of 11 years standing, her reaction might be said to be a little naive. Because enjoying being a girl is definitely part of Walter's New Feminism. The days when men were to be hectored, not snogged are long gone. What you do in the bedroom, and with whom, is your own business.

If pornography is what turns you on, go for it. And The New Feminism is full of feisty examples of women who believed in "girl power" long before the advent of the Spice Girls. Walter believes the judgemental stance of earlier feminists only succeeded in marginalising the important political issues they were addressing. Maybe she's right, though there are many women - inevitably older - who would need a lot of convincing, including hardliners Andrea Dworkin and Julie Birchill, and even Fay Weldon, whose new novel Big Women takes a fictional stroll along the path feminism has taken over the last quarter of a century. A totally objective exploration of feminism is perhaps impossible. Women's experience of discrimination, of how it has affected their lives, differs hugely, depending on their age, whether they have had children, whether they have been thwarted either in education and/or career (over 50), or traditional marriage-and-motherhood (under 40). Woman aged 70 who suffered discrimination from first to last may even deny its existence. Ditto young women under 25 for whom equality is as natural as breathing. Coming from a solid intellectual background (Cambridge and Harvard) Natasha Walter does her objective best. The book is anecdote free. "We" - as in "we women" - is not used in The New Feminism, and "I" and "my" are rare.

"When I first started writing, it was very much a book written from the point of view of `we', and that's very much a tic of feminist writing. I decided to move away from that. I didn't want to lock men out. So when talking about women, I use `they', which felt odd to me when writing but I thought it was important for readers to feel it wasn't just women who were being addressed. I really hope men will be reading it as well as women who haven't read much feminist stuff, and that was another reason for me deciding not to just take issue with what had gone before. Because it's very off-putting to open a book and think, `God, I haven't read any of that, it's in a tradition I don't know anything about'. Whereas if I write about women out there, women we know about like Harriet Harman or Cherie Booth, or women I can introduce, anyone can see where the author is coming from."

The hope that men will be among her readers is central to Walter's vision for the future. Although reluctant to accept responsibility for the part feminism has played in the breakdown of the traditional family ("There's no way we can go back now. We can't ask women to stay with men they don't feel happy with any more."), she sees the way forward as offering an increasing rather than diminishing role for men at the coalface of family life. "I think the main way to deal with the problems that family breakdown causes is to help men to feel more part of the family, so that if the family does break down, they still feel like a father to their children rather than just moving away and feeling that they don't have to nurture their children or provide for them."

At 30, Walter still vibrates with the optimism of youth. As yet she has no children of her own (she is in a stable relationship) but her just-turned-30 friends are all busy giving birth. Personal or one-remove experience of the reality of working-mother life, with or without a man around, has yet to hit her on anything but a theoretical level. For Natasha Walter and her generation the issue of work, and equality at the workplace, is all-important, although she is not blind to the potential danger this throws up in terms of the family.

"That's why I am arguing for a radical transformation of the way work is organised so that men and women can spend more of their time at home during their working years. But until men feel that necessity as well, things aren't going to change in the workplace - it has to come from men as well as women."

Although she doesn't hammer the point, Walter clearly sees male inertia as a problem, citing the example of popular culture - women's increased "ballsiness", the power-driven, sexual predators Edina and Patsy of Absolutely Fabulous measured against the increasing powerlessness of Men Behaving Badly's inept lager-drinkng couch-potato also-rans.

"Men have to come to terms with their changing roles. The way forward is not, `Poor men, we have to give you back your breadwinning role', because that, obviously, is not going to happen. Those jobs just aren't there, and women now have power in the workplace. They want to consolidate it. They don't want to give it back. But I think the answer is to say, you do have a place at home, you do have a role to play, and don't feel excluded."

Natasha Walter's parents divorced when she was a teenager. Her own father, she says, "has been a great support and inspiration" in her life. The divorce was obviously handled with great care. "In some ways it built up a closer relationship. I don't want to sound as though I'm condemning individual women for making that choice, but I do think it's a real pity if fathers are not involved with their children. And if men are involved, I think it means more for women's equality than if women are trying to do everything on their own. The onus is not just on the individual man, it's also on us to think about parenting as something that belongs to both men and women."

Walter also feels a strong debt to her mother, an old-style feminist who got her independence the hard way. "When she started working, she was price-checking in a supermarket. Pretty mindless things, until she got trained and got qualified to do what she wanted to do." First came a degree with the Open University. Now she is a social worker.

Blair's Babes may have been elected in last May's mould-breaking British election; half the medical students and trainee solicitors may now be women; but, says Walter, it's no time to be complacent. "As long as 97 out of 100 university professors are men, it's just crazy to say it's all done. There is an enormous amount of inertia. Women are still discriminated against. Young women are feeling very confident, much more confident than before, they're better educated, they're looking at their lives in a rather different way, but there's an awful lot of work that has to be done to get to equality." The New Feminism, by Natasha Walter, is published by Little, Brown on January 22nd, price Stg£17.50.