Recently a television producer, a real high-flyer, called me up. The problem, she explained, was that her daughter Poppy was getting frustrated when she tried to read a book. Her mother got frustrated too because although Poppy, 8, had a stock of words she could recognise — when she came to a new word she could not work it out. Teachers at her private school were starting to mutter about dyslexia. What did I think?

I observed the little girl for five minutes and realised straightaway that she had been taught to read by the “look and say” method of memorising words by sight. I showed Poppy’s mum how to teach her to sound out the words instead. They spent the summer holidays working together and by the end Poppy had increased her reading age by two years and hadn’t hurled a book across the room for weeks.

Poppy is at the tip of an iceberg. Over the past 12 years I have witnessed a national tragedy. Nearly a decade after the government introduced a £1 billion strategy to teach children to read, we have hundreds of thousands of children in our schools — even official statistics throw up one in five of all 11-year-olds — who can’t read properly. Some of them, including teenagers, can’t read at all and this is a scandal.

In one school in Leicester I visited as a reading consultant I met Siobhan, 12, who was pulling her hair out and seeing a psychiatrist. Siobhan was anxious about going to school because she couldn’t read. Now, six months after starting my programme, she can read. She didn’t need a psychologist, she just needed to learn her letters.

Then there are the silent sufferers like Conrad, 13, and at a London day school. Daily he devises an elaborate game of make-believe, stuffing Anthony Horowitz novels into his school bag to con his mates.

Parents be warned. We’re not talking about poor kids here, from homes where televisions are always on. I’ve seen plenty of kids from affluent families, just like the producer’s daughter, pupils at private schools, the 4x4 parked in the drive. These children are often labelled dyslexic or SEN (with special educational needs). Not a bit of it: what they are is, to borrow an American acronym, ABT — ain’t being taught.

The signs are there for mums and dads who care to look out for them. If you have a child who brings books home but doesn’t want to read them; a child who is suddenly either too quiet or too aggressive at school; a child who has clearly memorised her early books or who is being described as “possibly dyslexic” or “plateauing” by her teachers — be alert to the possibility that, no matter how old, she may never have learnt to read properly.

How has this terrible state of affairs come about? It seems extraordinary but how we teach children to read has for the past decade been the subject of a furious war. The casualties are our children.

Eight years ago I sat in a room in Portsmouth with a bunch of people who had all pitched their camp in these “reading wars”: the experts who thought children learnt to read by memorising words, the ones who wanted them to guess from pictures on the page and so on.

What was at stake was the shape of the national literacy strategy, by which children were to be taught to read in state primary schools. I argued that children must be taught to work out words using one method alone — synthetic phonics. Basically it means teaching children the 44 sounds of the English language and how to blend them together to make words.

Why did I argue my corner so ferociously? Because I had seen the evidence with my own eyes. At the time I was head of a primary school in London’s East End where most children were from Bangladeshi families. Although many of the parents couldn’t speak English all my pupils learnt to read, most of them by the age of six or seven.

But I didn’t win in Portsmouth.

I wept with frustration but what was finally agreed was a hotch-potch of everyone’s methods. Teachers would use a bit of “look and say”, a bit of phonics, a bit of guesswork. That’s what has been in operation ever since and the result is a generation of many illiterate children.

I joined a group of like-minded people to push the case for common sense from the sidelines. I was ignored, treated as a weirdo. But I’m not a weirdo; I am a woman who has worked hard to make sure that every child can learn to read.

Last week, finally, we were vindicated. Eight years on, the mess that emerged from Portsmouth is about to be dismantled. From September, thanks to last week’s report by Jim Rose, the former school inspector to whom ministers turned for advice on what to do about the country’s reading crisis, all schools are going to have to use synthetic phonics as the main way of teaching reading. Hopefully, all children will now learn to read by the age of six or seven.

It’s thrilling news. But it could all still go horribly wrong. It’s up to Capita, the IT company, (which was in the news rather a lot last week), and which has the contract to run the new literacy strategy, to make sure that this time the people who really know how to teach children to read are involved.

For parents I have one message. To make sure your children don’t slip through the holes in any future reading nets, never again assume that the responsibility of teaching your children to read belongs solely to someone else. Try doing it yourself too, using a phonics strategy. Let’s have no more casualties in the reading wars.

Ruth Miskin was talking to Sian Griffiths

For more information on how to teach children to read see www.ruthmiskinliteracy.com