School gates across Cambridgeshire were flung open last week to welcome pupils back for the start of a new academic year. For hundreds of 11-year-olds in St Neots it was that gargantuan leap to secondary school. I visited Ernulf Academy to find out more about the new Astrea Trust regime.

The first thing that stands out is the new uniform. A professional light grey, and all pupils are wearing blazers. A walk round the spotless building reveals a school that not only wants to teach, but is determined to inspire.

Inspirational quotes from Nelson Mandela, Rosa Parks and John Lennon adorn the walls, as do images of notable mathematicians and scientists.

Entry to classrooms across the age divide shine a spotlight on pupils who not only look smart, but who have, in an incredibly short space of time, embraced the new ethos and seem to understand perfectly what is expected of them. One or two are reminded about their posture, but all seemed genuinely engrossed in lessons.

Pupil numbers are currently 540 for Ernulf and more than 2,000 for Longsands, and the hope is that Ernulf will grow organically as the result of the massive house-building programme at Love's Farm and Wintringham Park and this seems to be borne out by the growing Year 7 intake in the last two years.

The new Ernulf principal is Avin Bissoo and Hywell Jones is principle at Longsands Academy and also deputy director of the Astrea schools in Cambridgeshire, which are St Ivo, Cottenham Village College and The Centre School, in Cottenham.

Mr Jones was head teacher of the country's first free school, the West London Free School, in Hammersmith. He says there were some highly disadvantaged pupils, some from war-torn areas of the world and he was the third head in three years.

"Obviously, there was a lot of interest from the coalition government as to how I was getting on as it was the first Free School. There was a real turn around situation. But I knew Astrea was working in Cambridgeshire and I have always lived locally and I thought the idea of shaping five schools in a trust of 27 schools would be absolutely brilliant," he said.

He acknowledges the disparity between the two secondary schools and admits there is work to be done to bring Ernulf in line with Longsands.

"Both schools in St Neots have had, on public record, serious financial issues," he said.

"They had a financial notice to improve from the SFA and that's never a good thing, but I have a deep financial background so being able to impart real financial stability and reassurance was important and we have achieved that in a short space of time.

"At the same time, improving the outcomes. In Longsands, I suppose that has been more rapid and in a school in Ernulf's position which has had a long history, some 30 years of 'middle-ing to poor performance', that's always going to take a little bit more time."

There are plans to re-introduce the parent association at Ernulf and a breakfast club and homework group have been set up.

The mobile phone policy (their use is banned in school and they are kept in bags) has largely been welcomed by parents. Pupils who fail to complete homework will be asked to do it at the end of the school day.

Mr Jones insists the trust is using "tried and tested" methods, which he is confident will bring long-term results.

"What we are doing here is not unique. We are using tried and tested curriculum materials that have been used across the sector to great effect. We aim to instil that academic hunger in pupils of all abilities," he said.

"Making sure there is really strong vocational offer for pupils aged 16-19 and in St Neots where there is a lot of small to medium sized enterprise and a really healthy manufacturing sector that we are looking to harness a new technical level qualification that should come in around 2022."

Mr Jones is confident that despite the history and problems of the past, there is now a growing and tangible sense of optimism among staff, pupils and parents.

He said: "We will build the numbers naturally, but we know we are going to have a much bigger number here, so it is incumbent on us to improve the school performance academically and then future plans for extensions and refurbishments are fully possible.

"There are a lot of possibilities and that, I would have thought, is really exciting for everyone."