My little boy has a place at nursery school for two mornings a week beginning this month. He may also have a hidden agenda. “If you learn to use the potty, you can go to nursery school,” I’ve said to him. At cross moments (sorry, Penelope Leach) it becomes: “If you don’t use the potty, you can’t go to nursery school.” No great step for his almost three-year-old brain to turn this into: “If I don’t use it, she can’t send me away.”

It’s taken me two and a half months and innumerable pairs of trainer pants to realise that he has his doubts about nursery school. He may not even be ready for it. Nursery schools and pre-schools (playgroups) are increasingly seeing children who aren’t ready. It comes down to peer and pecuniary pressure.

Jo Goodall, an early years advisor with Essex education authority, says, “There’s tremendous pressure on parents to enlist the child in a nursery school because they are frightened he may be disadvantaged if he doesn’t go.” Karen Walker, secretary of the National Private Day Nursery Association, stresses the economic reason for the rush to nursery. “The family needs two incomes and has to muddle through somehow,” she says.

Nursery school children react to the morning goodbye in all sorts of ways. Most are fine, though they may punish the parent with bad behaviour at collecting time. Some get terribly upset and are fine two minutes after mother or father disappears - Goodall actually recommends staff to have an Instamatic camera with a time line on it to reassure parents that their child wasn’t unhappy for long. But some are truly miserable.

Margaret Lochrie, chief executive officer of the Pre-School Learning Alliance, says: “Most children are ready at three, but there are children who find separation difficult. A good nursery school or pre-school will tell the parents if their child is unhappy. Parents may notice the child is clingy and not sleeping very well.” The Pre-School Learning Alliance says it has 60 per cent of three-year-olds and 30 per cent of four-year-olds. Margaret Lochire recommends starting with one or two mornings a week.

Karen Walker lists the signs of a child who is not ready for nursery school: “She will probably be really stressed about parting, will not integrate well, will play by herself, not even in the parallel fashion of the younger children, will not really be ready for sharing and turn-taking. At home she may be difficult about going to bed, and not want to get up in the morning because she’s dreading it. It may affect her eating. She may wet the bed.”

Having noticed this, a good nursery will do something about it. It may even be able to prevent it, according to Wendy Scott, chair of the British Association for Early Childhood Education. “I’d like to see more home visits before the child comes to nursery, so he sees the nursery worker on home ground. She might see how he plays at home and say: ‘I see you like puzzles. We’ve got a good puzzle at nursery school.’ “There’s a temptation to let the parents slip away without saying goodbye while the child is distracted. That child turns round later on, finds mother has gone, and the trust is destroyed. It’s much better if the parent says: ‘Right. I’m off now. Have a good time. See you later. ’ Nor do I like the rush by the worker to cheer the child up. It’s much better to say: ‘Yes, it’s really hard when mum goes.’ Respect the child’s emotions.

“I let a child ring Mum and say: ‘Hello, I’m fine. I’m going to have my milk and biscuit now.’ But sometimes it is simply too soon for a child. When I ran a nursery I would suggest trying again next term and I would keep the place open.”

Jo Goodall also believes there are ways of helping early on. “Most households have a video player. Why don’t nurseries video their activities so that the child can sit down at home and see what it’s like? Induction should revolve around the child. Nurseries and playgroups need to be more flexible. That may mean a drop-in day, or a day when Mum or Dad stays too.”

Karen Walker says: “The system we have doesn’t always allow for the child who is not quite ready. If you’re in a position where you can afford to pay you can say: ‘Let’s try a nursery where they have ages 0-5.’ The child can stay with the younger end. But state nurseries take the rising fours. Sometimes the place will not be held open. The best thing might be to get the child into a toddler group or a playgroup where he meets other children but stays with mother. ” And all agree you should avoid too many changes at once. Coping with a new nursery school at the same time as a new sibling, divorce, the death of a grandparent, or potty training, is too much.

For those mothers who could have their children at home, is nursery school worth the worry? Margaret Lochire says: “Children who stay at home are not necessarily at a disadvantage, if they have lots of books and their parents spend time with them and stimulate their curiosity. They learn to mix socially at a pre-school, though there are other ways of doing that.”

My daughter has just finished two years at two successive nursery schools. In her last term she was doing five mornings a week and loving it. When she started, on two mornings a week at two years nine months, we had no scenes when I left her. But there was the odd spat when I picked her up; the odd “Why did you leave me, Mummy?” on the way home - and even an “I don’t love you, Mummy”. Wendy Scott decodes it: “She’d been very brave all morning and behaved well for the nursery staff. She felt safe enough with you to show her anger, but she wasn’t going to tell them about it.”

I shall listen more carefully to her brother.