Jay should not have run out of school. He should not have scaled the fence, and he definitely should not have gone to the local pond and filled up his lunchbox with an oozing mass of frogspawn.

But at Gorton Mount Primary in Manchester, that was what Year 3 had been like that year - always running away.

Carol Powell had been warned. Taking on this school, one of the most challenging in the country, as your first headship will attract dire warnings. But in 2002 she went ahead and did it anyway.

The school, which serves the estate immortalised in the TV drama Shameless, had been brought out of special measures by the previous head.

But Ms Powell was the sixth head in seven years to take it on - and that meant taking on Year 3. Ms Powell set up a temporary office at the back of the classroom, tapping away on her laptop while the eight-year-olds learned their times tables - her presence was meant to help the teacher to keep the children in their seats.

Jay’s escapade made Ms Powell realise a few things - apart from the need for a higher fence. Now they had an idea of what Jay was interested in and could see that in order to learn about the world he had run out of school.

“That can’t be right,” Ms Powell reflected. So she called for help - from the Montessori Foundation.

That decision set the school and its pupils on the way to becoming the first state-funded Montessori primary school in the country.

The story of Montessori teaching begins in a slum district of Rome where pre-school kids were causing mischief while their parents were at work. Maria Montessori, the first woman to become a doctor in Italy, found a way of helping children to learn despite the fact that their lives were chaotic and money was scarce.

In the intervening decades, Montessori schools have become associated with certain strata of the monied middle classes - the nurseries are in Notting Hill rather than Newham, Hebden Bridge rather than Huddersfield. But this is now being challenged by Ms Powell and her 450-pupil school.

Built in 1927, the school’s tall, arched windows watch over the surrounding streets of 1960s semis and terraces. At the doorway, individual bricks have been covered in neat handwriting, each one detailing the articles of the Universal Declaration of Human Rights. Inside is another declaration: “The first duty of education is to stir up life but leave it free to develop” - Maria Montessori.

In Ms Powell’s office, the floor, shelves and desk are covered with teetering piles of files and folders. A pink pelargonium stretches from its pot on the filing cabinet towards the head-height window opposite. It doesn’t look very Montessori - the method lays great store in being neat and tidy. Ms Powell laughs and swears she will tidy up on Monday.

“There isn’t another school like this,” she says. “We have one statistical neighbour, in inner London.”

The statistics are daunting: 69 per cent of children are on free school meals; 52 per cent are learning English as an additional language; 39 children are asylum seekers or refugees; 54 per cent have special educational needs and 151 of the 456 pupils are on the school’s child protection log.

“We did want blue walls,” confided one staff member in a nursery so uniformly mild yellow that it gives the feeling of having been plunged into a tub of churned butter. “But it wasn’t Montessori.”

Many early-years classrooms look similar. They have role-play areas, small world trays, art tables and water tubs and their walls are covered with displays of children’s artwork as well as posters about their interests - insects, snow, the World Cup. The children can make models or use the computer, feel shaving foam or race pedal cars.

But Gorton Mount nursery is different. It is the end of term and the walls are almost bare, with only a picture of a train whose carriages are the months of the year, a map of the world and four framed collage prints of sea creatures.

The furniture is wooden and low shelving snakes around the walls. On the shelves are wicker trays, each with a single activity. A child wanting to learn pulls out a tray, picks somewhere to work - at a table or a mat on the floor - completes the task and puts it back. One tray contains a tweezers and two boxes - one full of spills. The child transfers the spills one by one with the tweezers to the other box.

Other equipment includes a tower of solid cubes, a wooden shape sorter which consists of a single line of cylinders in descending sizes, and a box containing mounted glass slides, each one a single colour.

The approach has also promoted learning through play and teaching through observing for more than 100 years - principles which are now two of the cornerstones of the Early Years Foundation Stage, which all early-years settings in England now follow.

Val Penoyre, head of the school’s foundation department, looks like the kind of smiley, warm-hearted woman who would get eaten alive at a teddy bears’ picnic, let alone an inner-city primary school, but she has been working here off and on for 30 years and has no illusions.

“This area has got tremendous challenges,” she says. “Carol realised we needed to help children who were battling with life on all fronts.”

The Montessori St Nicholas charity responded quickly to Ms Powell’s plea for help. She rang in Easter 2005 and by September the same year they were ready to go. The then Department for Education and Skills agreed on funding of #163;40,000 for the experiment and that figure was matched by the charity.

Over the summer holidays, rooms were stripped and set up as Montessori classrooms, and it was decided that a Montessori trainer would work full-time with the staff for two terms.

“It was quite drastic and quite frightening throwing out the old and starting something different,” Ms Penoyre says.

“A tremendous challenge, but I was very enthused by it. I like the simplicity of Montessori. In all my many years of teaching, I have seen many initiatives come and go. But this has stood the test of time.”

Still, not everything was thrown away - some of the equipment ended up being stored in various cubby holes and under the stairs.

Then there was the culture clash between the school’s designated Montessori trainer, who had moved up temporarily from her peaceful thatched village in Essex, and the staff in the large primary, which was being constantly buffeted by social forces.

The official evaluation, paid for by the Montessori St Nicholas charity, sheds some light on the year. Children were thrown by returning to classrooms where their familiar toys and equipment had disappeared. Parents were disgruntled at being asked by the trainer to remain outside to allow children to settle.

A report of a single morning in December describes how children, although not misbehaving, were not learning. Instead, they were chatting, playing, running until “the clearing up period dissolved into apparent anarchy, with children cheerfully climbing onto furniture and window ledges”.

In the spring term, relationships between the trainer and staff deteriorated. The trainer was concerned by the high child-to-staff ratios in the mixed-age classes and was asked to work outside the classrooms and continue the staff training one to one.

When Ofsted arrived in January, it noted the calm and purposeful atmosphere in the classrooms but also pointed out the need to monitor progress more closely. More staff were drafted into the classrooms and things began to settle.

In the summer term, the project passed entirely into the hands of the school, although staff decided they were not going to be too purist. Lego started creeping back and displays went up.

“It appeared that the staff had decided which of the Montessori resources worked well for them and utilised those intensively rather than adopting a Montessori approach across the curriculum,” reported Dr Liz Brooker.

Ms Penoyre clearly agrees with this summary. “It can be like a religion,” she says. “You do find people within it who refine the thinking to the point of boredom. We are going for the essence of it, like Maria Montessori - she did it to get children off the streets.”

Dr Brooker’s report ended on a supportive note, praising Ms Powell for her vision and noting that a new alliance with the Montessori St Nicholas charity was being forged.

She says: “The project must be described as successful in one fundamental respect: that this enormously challenging intervention was planned, funded, implemented and brought to a satisfactory conclusion.”

Ms Powell says: “I could have got a headship anywhere and I could have been bored to tears now. It’s not boring in this place. And I do have a political view of education giving you opportunities and making changes to communities. I do think it is a universal human right to be educated.”

And Jay? He is still remembered in school as a great climber - a talent that helped him shine at the Year 6 residential camp in the Lake District.