'WHY DIDN'T I use a condom? She didn't mention it so I presumed it was okay. Besides, I was drunk. I'll admit that I was stupid but there's no way I deserve this kind of punishment. Eighteen years is one hell of a sentence for a one-night stand.'

Alex, an actor in his mid- twenties, has just been contacted by the Child Support Agency. A year after a one-off night of casual, unprotected sex with a woman called Kate at a drunken cast party, he has been informed that he is liable for maintenance payments for his and Kate's baby daughter (a child he's never seen), until she is grown up and out of full-time education.

Alex is outraged. 'Unlike most of those guys that the CSA are after, I didn't walk out on a family. It wasn't even a relationship . . . We both had a good time but that was it. A classic one-night stand. When she rang me up three weeks later to tell me she was pregnant I didn't believe it was mine at first. She only rang me in the first place to tell me she was pregnant out of politeness,' he says. 'I tried over and over to persuade to her to have an abortion. But she said it might be her last chance at motherhood - she's 37 - so she said no.'

He says they went their separate ways, agreeing to have no further contact, and to leave his name off the birth certificate.

However, when Kate had the baby, decided to give up work, and signed on for benefit, their deal came apart. The CSA told her that money would be docked from her Income Support for the next 18 months unless she revealed the father's name - now standard procedure unless the mother can prove (or convincingly pretend) that either she never knew the father's surname, address or phone number, or that contact with him would elicit violence or similar undue distress.

'She says she held out for about six weeks and then I get this.' Alex waves a wad of CSA correspondence. 'I don't know who I feel more angry with, her or this bloody Government. They didn't exactly advertise this kind of scenario, what might happen, did they?'

Advertise what, though? The rules haven't changed about Alex's paternal responsibilities. Men like him were always liable for maintenance. But, before the Child Support Act, they could reliably bank on a woman never having the resources, time or determination to chase them through the courts. Perhaps the CSA and the Department of Social Security might have advertised to Kate (and other happily single mothers) that she would either have to face months of enforced poverty, or break a promise to the man they tried to leave behind?

Alex doesn't see it that way. 'She promised I wouldn't be involved. She should have stood by that and taken the consequences. It is unfair that I have to support her whether I wanted the child or not. It seems I've got all the responsibility and none of the rights.'

These objections fall on deaf ears at the CSA. 'The Act makes no distinction between whether the man was with the woman for 20 minutes or 20 years,' says a spokesman.

Liz B is a counsellor for a pregnancy advisory service. She is becoming familiar with stories like Alex's and is less than sympathetic. 'It's a new phenomenon. I've had four calls over the last couple of months from men - all in their twenties and thirties - where women have decided to stay pregnant after a single night of mutual contraceptive irresponsibility. It's a fair bet that the mother will want to give up work at some point, and these men find it hard to accept that now the CSA is bound to implicate them financially they still have no say in her decision.'

None of the men she mentions directly proposed that they thought they should have rights over the foetus but it was 'definitely in the air', says Liz. 'They're all depressed. One was even suicidal . . . It's my job to be understanding but privately it's my opinion that they gave up any rights they had when they failed to used a condom. If they don't want to be fathers, then they must take responsibility for where their sperm goes. Afterwards it's just too late. Putting your fate in the hands of a woman you hardly know is incredibly nave.'

It is clear that, since the advent of the Pill, some men have stopped thinking that contraception is their responsibility too. But the advent of the CSA might eventually get the message over more effectively than any number of sex education lessons in schools. While he is pondering the subject, John Patten might look to Australia where the CSA has been in operation since 1989. Sex education there now concentrates as much on the facts as the morality and theory of sex. Classes are given a CSA information pack and an accompanying video - a 'docudrama' based on a real 15-year-old boy who found himself a father. 'We discovered that when we simply asked the kids to play the 'what happens when you grow up and get married and divorced and end up paying child support' game, they just yawned and didn't pay any attention,' comments Australian CSA press officer Lydia Buchtmann. 'The real life stuff is much more effective.'

A similar schools package here might help in the future. In the meantime more men, of all ages, are beginning to realise that that they can no longer afford to take a woman at her contraceptive word. Jock's story is a case in point.

When he went to bed with Sally for one night, he asked if he needed to worry about contraception. She told him he didn't need to bother, she couldn't possibly get pregnant. He says she lied. 'Sally's diaphragm was right by the bed but she didn't use it because she said it was the wrong time of month . . . She's an intelligent woman. Surely she knows there's always a risk of pregnancy? The fact that she didn't use it suggests to me that perhaps she had ulterior motives. Even on a subconscious level.'

One might privately wonder about Jock's own subconscious. 'This has made me realise, for maybe the first time,' he says, 'that sex has serious repercussions . . .'

It seems that the already frail goodwill between the sexes may be tested further now that sex is officially a 'cash issue' for men. Some might say it's always been that way for women. 'I think it's a sad day when you find yourself not being able to trust a potential sexual partner,' says Martin Lloyd-Elliott, a psychologist who deals with sexual problems. 'But this Act is potentially very revolutionary. Men will really have to wake up, in a way they've never had to before, to the full potential of their actions. That must be a good thing.'

(Photograph omitted)