When Rachel Boutonnet finished a reading lesson with her class of seven-year-olds at Goussainville in the northern Paris suburbs, she wiped the blackboard of any evidence of what she had been teaching. She also made sure that the textbooks they used — bought with her own money — were covered to disguise their contents.

The reason for this extraordinary furtiveness was that she knew what she was doing was flying in the face of French educational orthodoxy — a flawed system she believes to be a betrayal of the children she is dedicated to educating. But now her secret is out, in a book that has sent shockwaves through the educational establishment and worried parents all over France.

Her message will resound, too, with British parents, who have agonised for years that their children are not achieving their potential, only for teachers to dismiss their fears with educational jargon that flies in the face of common sense.

The Diary of a Clandestine Teacher analyses how the dogma of child-centred learning has robbed teachers of what she sees as their key role: the authority to impart knowledge.

With her glossy skein of henna’d hair scraped back in a clip, her granny glasses and grey T-shirt, jeans and clumpy boots, Boutonnet, 31, looks more like a fully paid-up member of the teaching caste than its scourge. But her “principles of reflection and understanding”, honed by a degree in philosophy at the University of Nanterre, obliged her to speak out.

“My vocation is to be a teacher in the public system — it is important and precious — but for Sarah (her eight-month-old daughter) I envisage private school because I see the state system is not good enough. Ten years ago I would never have said that. It’s a shame.”

French parents are increasingly turning to private education, she says, partly because of recent strikes in schools but also “because of what I describe”.

Boutonnet began keeping her “secret diary” in 1999 when she embarked on a course at IUFM, a teacher training college in Paris, and realised that her views on what children needed were wildly at variance with what she and her fellow students were being told. She soon realised dissent was not tolerated. (“You’re in the belly of the beast now,” as a friend remarked.)

So she remained silent, even in the face of such fatuous ideas as preferring the information on a pot of yogurt to a proper book as reading material. Much was made of the teacher’s role being to inspire the “desire to learn”. “All children have the desire to learn,” Boutonnet says coolly. “What they don’t always have is the desire to work.”

She says she was not given the tools with which to effect the work of learning: “In all, six hours of the year’s course were dedicated to the teaching of reading and writing.” Much more time was spent on such concepts as “self-evaluation” by children (“No,” she says, “the teacher should evaluate a pupil’s work; the pupil does not have the qualities for self-evaluation”).

Her biggest gripe is with the insistence on “whole word recognition”, rather than on the phonetic principles of reading — which is why she imported the samizdat old-fashioned textbooks she thinks equip children with the tools to decipher any word, rather than having to guess each new word they come across without being taught the sounds of its component letters.

She has faith that her methods work, speaking with obvious warmth of the progress of each child in her class of 26. She’s in a tough school in a deprived area, with a large ethnic mix. “A child who is learning nothing becomes violent and naughty. But for the theoreticians, these children don’t exist. Though thousands emerge from the system every year unable to read, teachers simply blame it on social conditions. Yet I have seen such children calm down when they start to understand. The best thing is to ask a lot of them.”

Now that her book has brought her acclaim — she was even rung up by a presidential adviser on education soliciting her views — what does the future hold for Boutonnet? “I want to write another book — on reading. And I want to carry on teaching. There are wonderful moments. And it did me good to talk publicly about what was going on.” British parents might welcome hearing the voices of similarly committed undercover agents in our own schools and colleges.

At least now Boutonnet no longer has to wipe the blackboard clean after every lesson.