Just good friends...

In the 1989 film When Harry Met Sally, Billy Crystal delivered the immortal words, "Men and women can't be friends because the sex part always gets in the way," and set the tone for a generation of relations between men and women. Friends, Sex and the City, Bridget Jones - the moral of all those Nineties dramas was, don't kid yourself - eventually you're going to get together or drift apart.

"When Harry Met Sally set the potential for male-female friendship back about 25 years," Dr Michael Monsour, professor of communications at the University of Colorado at Denver, observed at the time. "Almost every time you see a male-female friendship on TV, it winds up turning into romance. Think Sam and Diane [Cheers] or Chandler and Monica [Friends]. These cultural images are hard to overcome."

Yet maybe it is happening at last. Next week Stephen Poliakoff, in his new TV drama, Friends & Crocodiles, sets out to prove that we've all grown up since then. The film tracks the decade-long relationship between a boss and his female secretary. We keep waiting for them to turn into lovers, but they never do. "I've always wanted to write a relationship between a man and a woman that was not a conventional love story," says Poliakoff. Similarly, one of the joys of BBC2's Extras was the platonic friendship between Ricky Gervais and Ashley Jensen. As Jensen observes, "Why is it that just because there's a man and a woman there needs to be a romance? I mean, not every man you meet has to be a potential suitor."

In a recent survey conducted by Friends Reunited, when respondents were asked "what's more important - being friends or being lovers?", nine out of 10 women and eight out of 10 men said it was most important to be friends. And 35 per cent of women and 41 per cent of men said their "very best friend" is a member of the opposite sex.

People like Mariella Frostrup, who regularly accompanies her old mate Hugh Grant to premieres and who values male friendships enough to salvage a long-standing one with George Clooney after briefly dating. Clooney is now a close friend of her new husband, Jason McCue. Or Nicole Kidman and Russell Crowe, antipodean allies in Hollywood and close friends for years. He is famously protective of her and, when her marriage to Tom Cruise broke down, whisked her and her children away for an island holiday. Or Sadie Frost and Sean Pertwee, whose friendship was established while she was married to Jude Law.

I have known my best friend, Michael, for two decades. He's the man I look forward most to seeing. He's eccentric, generous, opinionated (sometimes impossibly so). My women friends say he gets handsomer as he gets older. I take their word for it - we've never fancied each other. I genuinely believe it is possible, desirable even, to have a "friendship attraction" devoid of lust.

Denise Knowles, a relationship counsellor with Relate, agrees. "One of the big things I am confronted by in my counselling groups is, 'I just don't understand her' or 'I don't understand him'. Men and women do think and feel differently. Therefore, the more exposure you have to the way the opposite gender thinks, the more likely you are to have some understanding."

I am not a natural man's woman. Growing up in the north of England in the 1970s, my male relatives were not talky men. Most of my education was spent with women. My romantic relationships with men have been bumpy. Michael and I have seen each through divorce, bereavement, redundancy, three children (his), and several passive-aggressive cats (mine). We have our differences. Jewish and teetotal, he loathes the fact that red wine makes me tactless. I wish he would stop procrastinating and finish his bloody play. But I have no doubt this one is built to last. It's a different kind of love affair.

Because platonic friendship is about love. In ancient Greece, Plato's ideal of pure, spiritual love between men became known in Latin as "amor Platonicus". Eventually the ideal of "platonic love" was expanded to include non-sexual love between men and women. And the reality is that friendships of all sorts are becoming ever more important.

We stay independent for longer as we delay pairing off and having children, or don't have them at all, and we are likely to come back into the fold at different times, following break-ups. The American grassroots movement Quirkyalone has become a major phenomenon. Quirkyalones are not anti-love and certainly not anti-sex - merely "anti-dull relationships".

For centuries what psychologists call "voluntary gender segregation" was the norm. At parties women gathered in one corner and men lurked in another. Today boys cook, women play football and equality is a given. They cross paths more often, inhabit each other's worlds, and the mystery is eroded. Which leaves more room for friendship.

Carol Vine, a scriptwriter, 33, has been friends with Maurice Yeoman, an actor, for 11 years, since college. "It's wonderful to have a relationship with a male, knowing there's no chance you're ever going to hurt each other in 'that' way," she says.

Not everyone is convinced. "I think you can have a friendship without sex but I don't think you can ever exclude the possibility," says Phillip Hodson, a fellow of the British Association for Counselling and Psychotherapy.

So are we kidding ourselves? Behind every great platonic friendship is there a delicious game of denial going on? Or one partner secretly longing and waiting, the other basking in the glow of their adoration?

"I have to admit I know at least two of my male friends have always been a bit in love with me," says Deborah, an artist. "I find it creepy but also quite reassuring." Hodson believes that some people are definitely incapable of platonic relationships: "A person who is sexually incontinent or exhibitionistic, who needs to know the other person is responding to them in the full range of responses, couldn't stand it," he says. "They would flirt and drop their knickers at the drop of a handkerchief."

Even without any knickers being dropped, there is always that great spanner in the way of lifelong platonic relationships - the husband or wife. Knowles believes things have changed here as well - where once couples only had couple friends, "younger people tend to go around in gangs and they form these friendships that are very dear to them, it's almost like a community". Platonic friendships are more likely to be allowed to continue even after marriages or sexual commitments have been formed.

But even if there is no sexual betrayal, how many people feel really comfortable about their partner sharing his or her closest feelings with someone of the opposite sex? "My relationship was wrecked by one of these so-called friendships," says Kate. Her husband made friends with a neighbour at the school gates, who started to come round while she was at work. "What hurt the most was the intimacy - him telling her private things about our relationship or me. I discovered he'd worked on her house free of charge while I was out at work trying to pay bills and that he'd bought things for her. It was never an affair but it was just as hurtful."

Truly great and lasting platonic friendships are probably rare but they are worth fighting for. Michael and I didn't see each other for seven years. I can't even remember what we fell out about. He was divorcing, I was a bit deranged after a love affair. But, more likely, I was tired of having an older male mentor and he was tired of being one. We sent unkind letters.

Seven years later, I travelled to review an exhibition and saw a painting we had often argued about. And, dammit, I realised he was right. A wave of longing hit me. I decided to send him a card by looking up his mother in the phone book - I didn't even have his new address. But on the train back I changed my mind, it would be silly, immature.

I stepped off the train at King's Cross, and there was Michael on the platform in front of me. Quite by chance, he was meeting his son. "I'm much nicer now," I garbled. "I'm not," he grinned. And that was it. Bang, we were off again.

Case Study: 'I'd give up two limbs to save his life'

Letitia Scobie-Dalrymple, 30, Radio 1 Sunday Surgery DJ

I met Manjit at college when I was 15. We played pool together and I beat him. I suppose we were both misfits and we stuck together. He had a wicked sense of humour and a funny squeaky voice. We had a laugh.

He was a good-looking boy, he dressed well, he was very smart and very ambitious. I suppose I should have fancied him but I didn't, I'm not sure why. We ran away from home together when I was 17 and shared a bed at a friend's house but it was always totally platonic. Over time we have become like brothers and sisters. He is the person I'd share my last doughnut with. He tells me if I'm being stupid or if I need to go home - I'm the same with him. We totally trust each other.

It's really important knowing what he thinks about my boyfriends and vice versa. The big test for new partners is always meeting the best friend. I have liked most of his girlfriends but even if I don't, I would only say something if he is unhappy. I'd tell him afterwards though. He has been going out with someone for a couple of years now but it hasn't changed our friendship. There was only one evening a number of years ago when things were a bit blurred. He'd just had his hair cut and he was sitting on the floor and I was rubbing his head. He asked me to stop because it made him feel funny. I stopped and we sat in silence for about an hour and then everything went back to normal.

I would always say avoid sleeping with your friends because it rarely works out. It happened once with me and it's awkward and difficult and it will always mess up your friendship. There is maybe one person I would give up my finger for to save their life, another person maybe a hand. But I would gladly give up two limbs if it meant saving Manjit's life. That's how important a friend he is.

Manjit Kandola, 32, audio-visual technician from Streatham, south London

We were both quite young when we started hanging out together. It was always a case of being friends and never anything more. She is a pretty girl but I never really fancied her. I just enjoyed being friends with her. Our friendship has evolved. Her family have adopted me over the years. They treat me like a son. I suppose Letitia and I are more like brother and sister. We have never argued, which is quite unusual - it only takes one look or a raised eyebrow to communicate that there's something wrong so we've never really needed to argue. Some partners can feel threatened by our friendship and I suppose I can't blame them. Letitia was with a boyfriend for seven years. I met him when I came back from travelling and he was a bit like "who is this guy?". But it was fine after a while and I was soon going round to visit him even when Letitia wasn't there.

I met my current girlfriend on a night out when I was with Letitia so she has known from the start how close we are and it has never been a problem. She has her own platonic male friend who she goes out with too. Some friends I know have got together but it's never really worked out and it can be hard to pick up the pieces. It tends to affect whole groups of friends. I suppose our friendship is about having loads of fun and good times together. I definitely think it's possible to hang out with a girl and keep it platonic. Maybe the older you get, the easier it becomes.

Interviews by Danielle Demetriou