One-in-six Norfolk schools have been told their performance is a cause for concern, it can be revealed today, as the county council ratchets up the standards it expects of them.

A total of 72 primary and secondary schools have been placed in Norfolk County Council's bottom category following a risk assessment during the first month of the new school year, because it believed their achievement was not good enough.

This number, which includes academies and non-academies, is broadly similar to last year, but the council said this was not because there had been no improvement in the past 12 months, but because it was setting the bar higher.

It said 28pc of schools are in its middle category - those that require improvement or are not yet rated 'good' - while it has rated just over half as good or outstanding.

The council refused to say which schools are in which group.

Suffolk County Council introduced a similar rating system last year, and in March it put 88 schools in its bottom 'red' category, with 135 'amber' and 76 'green'. It, too, has refused to publish which schools are in which category.

Cambridgeshire County Council's school improvement strategy for 2014-16 aims for 88pc of schools to have a 'good' or 'outstanding' Ofsted rating by August 2016, compared to 74pc in August 2014.

Chris Snudden, head of the education achievement service at Norfolk County Council, said: 'Schools that cause us concern have significant issues about achievement of pupils. Some might be very well led, some judged 'good' by Ofsted as recently as last term, but the outcomes cause us concern.'

The council uses the risk assessment to define its relationship with schools, and Mrs Snudden said: 'With schools causing concern, we are very clear we have an intervention relationship, which means they are going to get us, whether they want it or not.

'In the other two categories, the schools are in the driving seat. We expect them to engage with us, and if they don't, that might cause us to risk assess them as schools causing concern.'

The concern about achievement could relate to overall results, or particular subjects or groups of children.

This is the third year the council has risk assessed all state-funded schools in the county, and it has toughed up its criteria ahead of the government introducing a new category of 'coasting schools' which could be turned into academies after their 2016 results are known.

Mrs Snudden said: 'The enhanced criteria we are looking at this year is partly linked to the Department for Education's coasting criteria for 2016, but it partly recognises that we have got a number of schools that might routinely perform above the Department for Education floor standard, and be judged 'good' by Ofsted, but that is possibly still an underachievement for those children.'

Schools in the bottom category are assigned a district intervention officer, who will meet the school 'quite regularly' and agree an action plan, and those rated 'causing concern' for the first time will see their provision audited.

The council expects schools in the middle category to buy into its Norfolk Better to Best programme, which gives them a programme of challenge and support tailored to their situation.

It will encourage schools in the top category to help other schools to improve.

Mrs Snudden said primary schools rated cause for concern last year posted an average six percentage points improvement in their exams results, compared to a one percentage point rise for other schools in the county, and nationally.

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