Charlotte Roberts and her husband had always been happy with their nannies in the past. Then along came Clare. We continue our series on the anxieties of the Nineties with a story of how professionals on top of their careers can lose their grip at home

Downstairs I can hear the cheerful voices of my two youngest with our latest nanny, a jolly, caring, helpful and apparently straightforward Antipodean, who "lives out" and has an active, but not intrusive, social life.

But three months ago I had to sack Clare, our nanny of almost three years - and sacking a long-serving, live-in nanny is inevitably a fraught experience.

Clare was introduced to us by a reputable, London-based nanny agency. Both my husband and I have demanding jobs and we needed an experienced, live-in nanny for our three children, who were then all under four. We had already been employing nannies for three years. I checked Clare's references carefully by phone, and all her recent employers said she was wonderful with children. So she moved into our house and, though painfully shy, settled in quickly. We talked through a written contract for child care duties from 7.30am to 7pm, plus baby-sitting two nights a week, and she did this with apparent ease. Never mind that in the first few weeks she had a few drunken nights out at the weekends. That was none of our business.

We all muddled along quite happily for two years. We even enjoyed the approbation of having happily kept our nanny for so long. But then we rounded into 1997.

Clare had been a nanny for 12 years and was clearly fed up with it - she said that while she was happy looking after our children, she wanted to do more with her life. So, having helped her complete a formal child care qualification, we discussed what other training she might do while working for us, and what career she might move on to. I introduced her to a career counsellor and some other contacts - but she went round and round in circles, unable to decide what to do. Then we noticed that far from her planning to move on, we had in fact become the focal point of her life.

Her social life - always scraped together in a rather desperate fashion and focused on getting drunk - had all but disappeared. I found her tipsy and in tears in her room one night, saying she felt unloved and unwanted. "Why do people keep letting me down, why don't they make the effort to go out with me?"

On reflection, I realised that while the local nanny circuit was active for her by day, no one seemed to want to socialise with her in their free time.

Then, one Saturday night, she did agree to meet friends in a pub. She came downstairs to wait for her taxi, and was clearly drunk. She swept my youngest child into her arms for a playful cuddle, but then lost her footing and dropped her on the floor. Apart from shock, my daughter suffered no injuries, but we were furious. Clare was mortified, and only the arrival of her taxi brought the incident to an end.

Another night soon after that, we got ready to go out for my husband's birthday and were astonished when Clare appeared downstairs ready to baby- sit. We knew the sober Clare - quiet, shy, and buried in her fringe - and the drunk Clare - verbose, over-familiar, words slurred and clumsy. This was the latter. We went out nevertheless, felt sick throughout the evening and returned early.

The next afternoon I took a deep breath and expressed my concerns. She was mortified, and retreated into the fringe and a frozen silence. Eventually she told me that she was feeling depressed due to some recent bad news, as well as her worries about her future career. Yes, she would cut down the drinking and sort herself out. The next day I found a "So sorry" card, some flowers and, ironically, a bottle of wine.

But my good intentions backfired. All I did with my sympathetic chat was drive the drinking underground. She hid bottles in her room and regularly tippled at night - at weekends, as well as weekdays. When she reeled downstairs from her room, we were never sure whether we would find her just a bit chatty, or incoherent and dropping the kitchen crockery.

When is too much, too much? Her drinking was, as far as we knew, only in the evenings; we drink wine with dinner, a bottle between us, quite often. Did we have the right to tell her not to drink at night? We had endless discussions, testing our views against those of friends and family.

We had no further "serious" baby-sitting incidents, though we often felt uneasy when we went out at night. But then on two consecutive nights she baby-sat for friends of ours and returned home tipsy. Shortly after this we noticed that she was regularly helping herself to our wine without asking - in what must have been surreptitious slurps, even as we sat next door in the evenings. We moved the wine from direct temptation, but she quickly tracked it down and helped herself. So, with some trepidation, I had to talk to her again.

There was more mortification, more tears, more sleepless nights - mine and hers. During another sympathetic discussion with me she promised reform, but she didn't want to call the counselling services I had tracked down for her. Another "Sorry" card appeared, and some more flowers. We should have acted, but didn't; I was very busy at work, the kids seemed happy - why break it all up?

A few weeks later we went to stay with friends at a remote country location, and Clare came to help. The secretive and guilty night-time drinking came with her. One evening she joined us and our friends for dinner - something of a precedent, as up till then she had always preferred to eat with the children. She appeared downstairs drunk - she was unsteady on her feet, and slurring her words. At dinner she ate like a bird and drank like a fish, and became loud-mouthed and barely coherent. Something in me snapped - that was it.

Two days later, with my children safely away on a trip with a friend, I faced her: "I'm sorry, it's over - you have to go." With a massive intake of breath, she raced out of the house into the garden, where she ran round and round like a madwoman, screaming at the top of her voice, "No, not this. No! No! No!"

Alone in the house in the middle of nowhere, I discreetly hid the kitchen knives, had my finger at the ready to dial 999 on the mobile phone, and waited for her to calm down and come back in.

But calming down took a further three hours of hyperventilation and crying, endless pleading - "Please, please not this, I'll do anything, anything, but not this" - and pitiful phone calls to friends and family. I finally persuaded her into a taxi in which she was ferried to our London home, where a relative had been installed to ensure she did herself, and our house, no harm.

She moved out after a few days and, though her contract specified four weeks' notice, we gave her 10 weeks' money as a financial cushion. She went home and, to my relief, sought medical advice and counselling. But we are not off the hook yet. We have had letters, postcards, farewell cards, more "Sorry" cards, a stream of "Missing you so much and love you heaps" cards for the children, plus phone calls.

Also, more scarily, we have had to fend off requests to see the children, to pick them up from school, to ice their birthday cakes - and then, in response to our reluctance, a visit, "Just to say good-bye".

Yes, we should have acted earlier, because we put our children at risk, and we consumed so much energy discussing what, or what not, to do to try to be reasonable. But the dismissal was always going to be painful, and because of that we felt we had to be sure of our ground.

We may sound pathetically indecisive or negligent. To others we may sound unfeeling, judgemental and unkind. Whatever your reaction, just pray you don't find yourself in the same situation - the employment rule book won't help you, either.

The names in this article have been changed.

Where charlotte went wrong

Gail Aspland Robinson runs Childhood Nannies, an agency based in south London.

Far too many working mothers feel held to ransom by nannies. They tiptoe around them, worried that if they criticise the nanny she may take it out on the children while they are at work.

But most professional nannies can handle criticism - you just have to say it in the nicest possible way. Good communications are critical; if you let things slide, a minor issue can become a mountain. Aim to have an informal discussion at least once a month, when the children aren't around, perhaps over dinner. Say what is working well, but also what isn't. The more you get to know your nanny, the better you can manage the relationship.

Then, if they don't respond and you still have doubts, you should go through oral and written warnings. Nannies are now more aware of their employment rights, and you have to behave in a professional way as well.

In this particular case, I feel the mother could have taken action sooner. A nanny shouldn't drink when baby-sitting and Clare should have been dismissed at that stage, or at least given a final written warning. It wasn't a "one-off"; it is suggested she drank heavily. It is no different from taking drugs. When a nanny lives in your house you have the right to comment on what they do in their own time.

After completing an NNEB course, Katie Potter has worked as a live-in nanny for two-and-a-half years.

This story sounds horrific, and Clare was lucky to keep her job for so long. OK, lots of nannies have drunken nights out at weekends, but you don't drink on duty - which includes the time when you are baby-sitting.

It was good that the parents showed an interest in Clare's career, but I'm not sure they did enough to help her when she got depressed. They kept giving her another chance, even after she had dropped their child. She clearly kept on drinking too much. The children's well-being was in danger.

Peter Cullimore is chairman of child care at the Federation of Recruitment and Employment Services (FRES).

The legal position is that, unless there has been "gross misconduct", you should go through the formal disciplinary procedures - an oral and then a written warning before dismissal. But with a nanny, we recommend that once the trust has broken down it is time to part company. Children are involved, so it is probably better to ask the nanny to leave immediately and give her a month's pay in lieu of notice.

FRES's standard nanny contract of employment lists theft, drunkenness, illegal drug-taking and child abuse as reasons for summary dismissal. The parents should have taken action long before they did - I think, when the nanny dropped the child. If a nanny is drunk on your premises, you should say good-bye. Also, people with a drink problem are marvellous at concealing it; you just can't take any risks.

A nanny will build affection for children, but these parents made the mistake of letting her get too attached. A nanny must not become a substitute for the parents.