When Louis was three, his nanny began teaching him to read and write. Sylvia, his mother, was pleased, thinking it might give her eldest son a head start. “I would only see the end result and he seemed quite proud of it so I didn’t worry.”

Everything went well until Sylvia came home from work early one day to find Louis in tears of frustration. The daily two-hour session spent tracing letters and spelling out stories had taken its toll. “The nanny used to force him to do it. He was interested in doing it but his dexterity hadn’t matured enough for him to write properly.”

When Louis started school, teachers thought he was dyslexic (he wasn’t) and put him in a special needs group. After two years he had recovered his reading age and went back into a mainstream class. But this year, Sylvia noticed he was struggling and asked if Louis could go back to the special needs class.

Now eight, Louis is still feeling the after-effects of those early attempts at his ABC. He’s a friendly, intelligent boy, who can tell you facts you never knew about dinosaurs or Alan Shearer. Being left-handed hasn’t helped, but the basics of calligraphy elude him. “Tasks many children find easy, like writing W, he can’t do. He gets numbers the wrong way round. And he finds it difficult not to use very big letters.”

Sylvia doesn’t blame his carer, but the experience has changed her views on early education. For her second son, Justin, she found a nursery where the emphasis was on play. “If children could write their name by the time they left, staff felt they had achieved something. But there was no pressure.” Justin, now five, loves reading and will devour simple storybooks at a sitting.

As a child, everybody enters the world of words by a different route. To some, this vast unexplored territory can seem like a great adventure playground. But to others, it is a scary prospect.

That’s the belief of some early years experts who would say the story of Louis and Justin shows the danger of forcing formal reading lessons on children before they are ready.

On the face of it, the Government’s promise of a nursery, school or playgroup place for all four-year-olds by September and extra time for reading once they get to school, is a solution to the problem of poor literacy.

But the ”`start ‘em early’’ argument hasn’t convinced everyone. One senior Labour Party figure spoke out last December against formal lessons for four-year-olds. ”`We have too many four-year-olds in schools and evidence increasingly suggests we have got it badly wrong,’’ she told a Fabian Society seminar, whose rules preclude the naming of speakers. Such discontent within the Government’s ranks hints at a growing divergence of opinion between teachers and the authorities over when and how children should be taught to read.

Pat Nicholas, who runs a pre-school playgroup in Redruth, Cornwall, was astonished when an Office for Standards in Education inspector told her she should be teaching three-year-olds to form letters and numbers. ”`That’s too young. It’s not necessary to do phonics with four-year-olds. We work in consultation with the reception teacher at the local school and children don’t usually start phonics until they are in school full-time. But we are having to do this, and we are not happy about it.”

Dr Sally Ward, of the Speech, Language and Hearing Centre, London, says children should be read to first, then start to read words themselves before they are ready to begin writing. Natural curiosity will lead them to recognise words, ask questions and start to explore the text on their own. Her children read Peter and Jane books on their own at three. With a linguist for a mother, that’s perhaps not surprising.

But she says any parent who gives “masses of stimulation’’ in the form of stories and rhymes, can help their child become a good reader. “The method doesn’t matter. The crucial thing is that speech and language development is at the proper stage before they start reading.’’ She has found that early encouragement, rather than formal teaching, can promote a love of reading in children without ready access to books. In homes of families which watched a lot of television, she found that nine-month-olds who were taken aside and read to during quiet times had “huge” advantages in reading ability over their peers by age three. The final part of her study is due to be finished in July, when she expects the knock-on effects to be even more pronounced in the children, now aged nine.

The Steiner Waldorf schools work on the belief that children only become physiologically able to read at about age seven.

Children at Steiner schools start to recognise letters by making pictograms (M becomes a mountain, K is king, reflecting the alphabet’s origins in simple drawings.) They compose picture “storyboards”, which they read aloud (storytelling and listening skills are key precursors to literacy, the schools believe), and progress to copying familiar rhymes and songs.

Hand-eye co-ordination and finger dexterity are encouraged by recorder playing, sewing and other arts and crafts, ensuring that children are ready for the complicated business of joined-up writing around the age of six. Only when they are seven do they start to read printed text.

Sally Jenkinson, Steiner Waldorf’s early years adviser, says: ”`Certain physical processes aren’t complete until around the age of seven. If you go with these developmental changes, you are often in tune with the child’s particular competence rather than forcing something.”

One US study which took the long-term view - looking at the effects of early formal reading instruction from childhood to early adulthood - had startling results. The HighScope Pre-school Curriculum Comparison divided 68 three and four-year-old inner-city children randomly into three groups. One was taught in a traditional nursery school, another had formal teacher-led instruction, and in the third - the HighScope model - children and teachers set up activities appropriate to children’s stage of development.

When the subjects of the study were surveyed again at the age of 23, those who received formal instruction were more likely to have a criminal record or emotional problems, and had a lower average income. The study concluded: “Early childhood programs in which children initiate their own learning activities are superior to programs based on teacher-directed instruction.’’

Roy Blatchford, director of Reading is Fundamental and a former secondary head, believes formative years are crucial and that what happens before children get into the classroom is often as important as what they do once they get there. “What happens up to the age of seven is decisive. As a society we have to promote the enjoyment of books - that it’s cool to read, and part of contented living - like a good meal or video,” he says.

“Access to text is important from an early age and the role of parents and siblings is extremely important. But in many parts of the country, what children lack, time and again, is access to a book culture. It should be a part of growing up.’’