Parents are flocking to a new primary school in Sussex where pupils don't take tests

A nine-year-old boy walks into class with a rock, which his granny brought from the Arizona desert. What does his teacher do? Tell him to put the rock away because of health and safety; save it for a "show and tell" session later in the day; or build a class project around it?

At Lewes New School in Sussex the boy's teacher used the child's natural curiosity to design a project all about deserts. And she was able to do this because the school doesn't follow the national curriculum.

An independent primary school for children aged three to 11, its learning is child-led. "In the state sector curiosity is stifled, partly due to the testing regime," says head teacher Lizzie Overton, a former deputy head in the state sector. "There is an increasingly prescriptive curriculum that decides what the children learn months, if not years, in advance." In other words, if it's October it must be the Tudors.

To learn the pre-set curriculum, introduced in 1988, children are constantly tested. Today's school reports are often long lists of targets your child may – or may not – have achieved. It was this obsession with exams and assessments that drove parents to set up the Lewes New School in 2000.

Dissatisfied with what the state sector had to offer, Dahlan Lassalle relocated from London to Lewes so his two children, aged five and seven, could join the school, which is based on the Italian Reggio Emilia schools that put the learner at the centre of things.

"I knew what I wanted," says Lassalle, "I wanted my children to love learning. If you don't want your children tested all the time then there is very little option but to go independent."

But what if other children in a class don't want to study deserts? What if they all cried, "Boring!"? Overton says the theme is always broad enough that everyone will find something of interest. Another child recently brought in a banknote from Lewes's own new currency bearing the face of Thomas Paine, the English radical and former Lewes inhabitant. Thus began a history project, with some children interested in Paine and revolutionary America, others in the history of Lewes.

In a state school it's doubtful if a teacher would have the freedom to do this, and Overton is by no means the only one who sees the national curriculum as stifling and prescriptive. Take the reports produced by the Cambridge-based Primary Review, for example. The review is an independent inquiry into primary education in England, the first such inquiry for 40 years.

One of its reports, published earlier this year, argued that the narrowing of the curriculum, the testing, and the focus on literacy and numeracy, had contributed to a "state theory of learning". Test scores had risen since the mid 1990s "at the expense of children's entitlement to a broad and balanced curriculum", it found. The review's final report is expected next year at the same time as Lewes New School holds its first annual educational conference. The keynote speech will be given by the Oxford University Professor Richard Pring, the lead director of the Nuffield Review of 14-19 Education and Training, whose report is due to be published in October next year.

He says the issues in primary and secondary education are similar and that the number of exams for young people over 14 means there is very tight control over what counts as learning. On the other hand, many teachers appear to be breaking out of this with a range of initiatives, in collaboration with groups such as the Royal Society for the encouragement of the Arts.

Pring describes "an interesting tension" between the constraints of rigorous testing, and the desire to bring greater flexibility to learning. "It's exciting. I've been to many schools and while teachers feel massively constrained to get youngsters to pass tests, there is also a move towards more active and practical learning."

Overton is quick to point out that child-led learning isn't new. "Teachers in the state system have had the freedom to teach in this way taken away from them," she says. "On paper the national curriculum looks broad, but in practice the children are disinterested and disengaged. I'd like to see the state system reformed."