Every Sunday, columnist Melanie Phillips inveighs against the vanishing moral fabric of our nation in the Observer. Outraged and principled, she addresses social and political issues, including family break-up, divorce, crime and, of course, education.

This week she publishes a book, All Must Have Prizes, which will probably cement her reputation in educational demonology as a traitor to the liberal cause, an arch-reactionary and bogey-woman.

In the book she excoriates almost everything in the system - exam standards at GCSE and A-level, the rot in primary and secondary schools and the universities, trendy teaching methods, teacher training, the national curriculum, and the mandarins at the Department for Education and Employment.

Her tone is apocalyptic and crusading, just as it was when she addressed Prince Charles about education at a dinner he arranged at Highgrove, his estate in Gloucestershire. She foams about the way children are taught - or not taught - to read, about the decline of grammar and Standard English in schools, the demise of the essay, and about cultural relativism. The national curriculum tried to change the culture but instead was sucked into it, she writes. And the disaster is not confined to state schools. “It is also now engulfing the independent schools, which are trying vainly to stem the tide.”

She concludes: “Britain is now de-educating. The whole of the British education system, from infant classes to degree courses, has been corrupted.”

She is a strong character, rather stern and schoolmarmish in appearance and dispassionate in argument. At the heart of her critique is our modern culture - a culture of “libertarian individualism”. That culture, she says, is responsible for undermining “most crucially and disastrously” relationships between individuals, parents and children, teachers and pupils, and is “why there is now such a strong sense that everything of value is falling apart”.

Half the book is devoted to examining why the attitudes of a bohemian fringe, exemplified by people like AS Neill and Havelock Ellis, became the norm, as she puts it. The rot set in with the Enlightenment and Rousseau. Their ideas were interpreted by Victorian and 20th-century thinkers until we reached the situation today where morality cannot be discussed, the family has fragmented, and crime is a social plague.

Despite what people may think, Melanie Phillips insists she has not become a Tory. Her book blames the Left and the Right - the Left for egalitarian individualism in the social sphere; the Right for libertarian individualism in the economic sphere. “Neither stood for a culture based on altruism, fuelled by a principled concern for other people.”

Aged 45, and educated at London’s Putney high school andOxford University, Ms Phillips is what she calls “a traditional Jew”, not orthodox and definitely not progressive. Thus her view of the world is based on the need to organise society around reciprocal duties rather than a system of competing rights.

“That’s quite deeply rooted in the cultural traditions in which I was brought up,” she says. She keeps a Kosher kitchen and attends synagogue regularly. Her children progressed through Hebrew classes and were inducted into the faith through barmitzvah.

The “right-wing” label is used to marginalise her, she says, so she can be put in a box with other card-carrying Tories. Anyone who thinks she is right-wing should read the book, especially the chapter which denounces everything this Government stands for.

“What motivates me is a perception that the problem at the root of our society and at the root of politics of both the Left and the Right - although Tony Blair doesn’t fit into this - subscribes to a doctrine of possessive, libertarian individualism which is inimical to the kind of social organisation resting on duty and responsibility.”

That makes her a passionate critic of liberal-left shibboleths from within, not from without, she says. Those who accuse her of being a Tory are engaging in easy and stupid labelling. “It is a smear. It is McCarthyism and they should be ashamed of themselves.”

Married to Joshua Rosenberg, legal correspondent of the BBC, she has not always felt this way about education. Her conversion to her current robust view took a long time. Along the way she had to choose schools for her children, a boy and a girl, now aged 16 and 14 respectively. Ms Phillips, who lives in West London, failed to get them into her favoured local primary school. The other state schools she visited were not adequate.

“What my children needed was out of sync with what they were providing, ” she says. “I thought it’s a shame, but there you go. My children were already showing signs of needing a more structured environment than was going to be provided for them at that stage by the schools which would have given them entry.” So she went independent and her children have been attending fee-paying schools ever since.

The other influence was what she learnt about education as news editor and leader writer at the Guardian, where she worked before moving to the Observer. “Things weren’t quite adding up - something was going wrong that went beyond the explanation that it was to do with underfunding and government hostility. ”

When she began to write a column for the Guardian and tackled education she was inundated with letters. The majority, from teachers and teacher trainers were hostile, but a few were passionately supportive. She was amazed. “Over the years that followed my opinions were in no small measure shaped by the reaction I continued to get in huge quantitites whenever I wrote about education - the reaction that was deeply, deeply critical and the reaction that was passionately supportive,” she says.

It is clear Ms Phillips also incurred the wrath of some colleagues. This has saddened her, she says, and made for a “prickly” and “uncomfortable” life at times, a bit like having rows with the family. But things are changing and she has encountered more open-mindedness recently, she says. For her book, which took 18 months to write, Ms Phillips visited a “small handful” of schools. She doesn’t believe one learns a great deal from visiting schools. It is more important, she says, to talk to teachers and read the literature they are reading.

As you might expect, her solutions for education are radical: children should be divided up on the German or Swiss model to be educated separately, according to their abilities and aptitudes, with flexibility so that they can switch paths; vocational educational should be top-class; and the national curriculum reduced to a core of maths, English and history. That may not happen but the issues she raises will not go away.