It is the last period before lunch, and Class 3 at Oughtonhead Junior Mixed School in Hitchin, Hertfordshire, are grappling with some meaty moral issues. This week's lesson: respecting differences in people. 'Have you ever wanted to be different from the way you are?' asks the teacher. An eight-year-old puts up his hand: 'Yes. I would like to grow up more quickly because then I could buy a car and go to the pub.'

After the discussion, which throws up thoughts about different races, mental handicap and name-calling, the children split into groups to make up their own morality plays. There is a fair amount of floundering - 'We've got to find something the character's good at. I know, fighting' - and prompting from the teacher. A few children, like one boy with spiky hair, seem to grasp the underlying moral principles: 'You should think before you act,' he says. Others are way off beam.

Oughtonhead Junior is on an estate of Forties council houses that has made considerable efforts to shake off its reputation for crime and vandalism. It is one of 40 primary schools that were chosen to pilot a project which aims to teach children as young as five the difference between right and wrong. The project, devised by the Citizenship Foundation, an educational charity, and funded by the Home Office, will be launched nationally by the Home Secretary, Michael Howard, tomorrow. Ten thousand free teaching packs with the title 'You, Me, Us]' will be made available and Mr Howard hopes that primary schools all over the country will follow Oughtonhead's example.

He may be disappointed. A government initiative on moral education is bound to be viewed with suspicion by many teachers and parents. In fact, although the idea smacks of indoctrination, the citizenship project seems innocent enough: less a diktat on right and wrong than a way of helping children learn to make their own decisions.

But it may well be a waste of money. At the project's core are a number of stories with a moral message. Given the wealth of children's literature that already exists, this seems rather a pointless exercise. Every children's story ever told has a moral.

And morality has always been the business of schools, as Anne Moran, headmistress of a primary school in a Sunderland pit village for 21 years, points out. 'It's as though there is a vacuum that schools are ignoring simply because we don't have a timetable period when you do Morals. We're teaching morals from before the school day starts to after it finishes.

'It's easy to come out with statements about teaching children morality. What isn't easy is to give schools what they actually need - extra human resources, so that teachers can spend time with children who present difficulties. Another document coming into schools is not the answer.'

The idea behind the citizenship initiative is presumably to make everyone feel that something is being done about juvenile behaviour. The address that the teaching packs are distributed from - Crack Crime, PO Box 999 - gives an indication of its political motives. There is a growing concern, highlighted by the James Bulger case and headlines about nine-year-old rapists, that extends far beyond people immediately concerned with children. The kind of antisocial aggressiveness once associated only with some secondary schools seems in the minds of many to be filtering down to much younger ages.

But can learning about right and wrong in the classroom really affect behaviour outside it? Surely the most powerful lessons are learnt by example in the home. The influence of schools, restricted to about 30 hours a week, must be limited.

Yet Andrea Dawson, Class 3's teacher at Oughtenhead, is convinced that the scheme has had positive effects on behaviour since it was introduced two years ago. 'We've managed to get children to stop and think before they act,' she says. 'They're more aware of cause and effect.'

Even so, she is aware of its limitations: 'Last year the class did rules, laws and respecting property. The children could deal with it ideally - yes it's wrong to steal, no they wouldn't do it. But how much was really implemented, I don't know. Some children had taken it on board, but whether they would have done without the sessions, I don't know. But I do think children need these lessons because I don't know that it goes on a great deal at home.'

There's a double bind here. Moral education in the classroom is deemed necessary if it is not being done by parents and other adults. But morality can only be taught successfully if it reinforces messages passed on at home and in society generally.

The fact that there is often a conflict between the two presents problems for schools. Andrea Dawson says: 'One of my biggest dilemmas is dual standards. How do you get children to come to terms with the fact that what goes on at home and what they might be allowed to do there is at variance with what you're trying to teach them at school? We're expecting a lot from some children.'

Attitudes among Oughtonhead parents vary widely; some don't much care what their children are up to; the majority, like the parents I met, think morality is very important. But do they not feel that teaching their children right from wrong is nobody's business but theirs?

Sue Hills, who has two sons aged 11 and nine, says: 'It's the job of both. If it's the teachers on their own or the parents on their own it's an uphill battle. The school teaches what I want them to learn anyway - not to be spiteful, not to bully, to be polite. I do worry about their behaviour. They have so many distractions, and it's such a dog-eat-dog world. Unless they are helped through the maze, how are they going to find their way?'

But Sue Hills's husband does not share her enthusiasm for the project. 'He thinks schools shouldn't have done away with the cane and that they don't spend enough time on the three Rs. It's the parents who aren't in regular contact with the school and who don't know the details who might feel a bit threatened.'

Sue Hills has seen a gradual change in her sons: 'The lessons don't have a direct influence, but it comes out a bit at a time. It's stretched both my boys a lot. It's taught the younger one to be more patient, although he's still got a bit of a temper. It's taught the older one to be more confident and to help out a lot more. I just hope when my eldest goes to secondary school they carry on.'

Looking back on two years of moral education, Janita and her friends from Class 3 have mixed feelings. 'The lessons make you think a lot. Sometimes it helps you to behave better. In the playground children steal - well, they don't really steal, they just borrow things and then keep them. And fight when they've been told not to. If they would just listen a bit. But they don't, they just draw on the table and pick the varnish.'

And for Balraj, a nine-year-old Punjabi boy, lessons in morality have failed to eradicate the behaviour that most affects him: 'If I tell people to stop messing up my game they'll probably be racist to me. Talking about racism at school doesn't help. Some people choose not to listen. They were probably talking about it in 1992 when I was in the infants. And it's still going on now.'

(Photograph omitted)