I AM writing this with my six-month-old nephew on my shoulder. My sister is at work and, like 20 per cent of working parents who use relatives and friends to care for their children, I am offering my services for love and with pleasure. However, this is only a temporary arrangement and soon she will have to pay someone to look after him.

In the past, children were often left with neighbours and family because their mothers were forced to work through lack of benefits. Now many parents are unable to work because of the cost of child care and loss of benefits if they do. The recent horrifying case of the mother jailed for six months for leaving her two-year-old daughter alone at home all day while she was at work highlighted some of the issues - but failed to draw attention either to the rising costs of child care or the reduction in some forms of provision because of the Children Act.

And while single mothers or low-income families can be deterred from working by loss of benefits or lack of affordable child care, middle-income parents also face tough dilemmas as the cost of nurseries or minders squeezes household budgets to the breaking point.

When my first child was born, I wanted to go back to my teaching career. I took my daughter to a registered child-minder from the age of six months, where she was treated as part of the family. I returned to work happy that she was in good hands. In 1985, this cost me pounds 140 a month. My partner and I managed reasonably well but found it harder once we had to pay for her brother, too.

Nowadays, where I live in south London, one child would cost pounds 300 a month and two children pounds 500. This is not a lot for for a child-minder carrying out a very important job, but it is a lot for me to pay out, and would make a big hole in my earnings. If I were a lone parent managing on my pounds 16,000 salary as a teacher, it would not be easy.

Several of my friends have had to sacrifice careers because they cannot afford child care. Struggling to pay a mortgage, Karen and Nick, civil servants, took part-time jobs to care for their three young daughters, after finding childcare costs left them with too little money. They are happier and better off financially but concerned that they are losing their chances to develop careers.

Jennifer, a divorcee with two children, had to haggle over her salary in her new job as a personnel manager, explaining that her childcare expenses were pounds 25 a day. Her boss, a bachelor, was amazed at the cost and together they worked out that she would pay out pounds 40,000 in child care up to the point when the children no longer needed it. He gave her the rise.

The families in the worst position, however, are those earning too much to receive benefit, but not enough to afford child care. Where I live, council nursery places are available, at pounds 40 a week, to working parents if they earn less than pounds 15,000. Parents claiming benefit pay less, but generally, council daycare provision is only available to lone parents or those children who are 'in need', as defined by the Children Act. Parents who earn more than pounds 15,000 a year only have the option of a private nursery place, costing pounds 90 a week. While the Government claims an increase in registered nursery places, these are mainly in the private sector and the costs are too high for low-income families. All this is difficult enough if you are paying for a single child, but what if you have two? Some parents space out their families to help spread the cost, or choose to have only one child.

The problem does not end when children start school. Children as young as nine and 10 go home alone to an empty house from the school attended by my children, with two hours to get themselves into trouble before their parents return. Many estates are dangerous places to be alone.

School holidays are also a dilemma. After-school and holiday play schemes offer stimulating programmes of organised activities and visits but have suffered from cuts and the regulations of the Children Act, which are so stringent that some voluntary schemes will be forced to close. Play schemes, if full time, are liable for a pounds 100 registration fee and a yearly pounds 75 inspection fee. Yet many schemes operate on a shoestring.

So what are the solutions? While many parents rely on friends and relatives, and this is valuable in bringing families together, it can cause division. One woman I know has not spoken to her mother since a furious row over the best type of nappy to use for her baby. But older people have an important part to play in caring for small children. Their role could be formalised, perhaps with volunteers supporting after-school schemes.

My 71-year-old father-in-law picks my children up from school every day. He's a well-liked figure at the school gates and enjoys his new role. He amuses his charges with funny stories and bribes them to behave. There must be others like him.

Employers also have a responsibility to support child care. However, there needs to be flexiblity to meet the needs of parents and children. The Equal Opportunities Commission has called for parents, government and employers to work in partnership for appropriate child care. Voluntary groups campaigning for improved facilities in the workplace emphasise the importance of government investment. Vanessa Schepers, director of Working for Child Care, stresses the need for a national strategy. Tax incentives and vouchers do not increase and improve provision countrywide.

Society needs to invest in the next generation. Leaving a child at home alone should be an option no one should ever have to consider.

Working for Child Care, 071-700 0281; Daycare Trust, 071-405 5617; Working Mothers' Association, 071-700 5771.