How Suffolk schools are rated by local education chiefs is being kept secret – because they say releasing the information is “not in the public interest”.

Suffolk County Council has refused a formal request from the EADT for information about the Red, Amber and Green (RAG) ratings for all of the county’s 299 schools. The RAG system was introduced last year as part of a school improvement programme – but has already caused controversy.

The EADT submitted a request, under the Freedom of Information Act (FOI), but education officials say that the release of the data would cause a “chilling effect” and prevent “free and frank” advice or exchange of views between education officers and schools.

In the last ratings, 88 schools were “Red” – almost one third of the total. Almost half of secondary schools are rated red.

The FOI response also said the information was “confidential” to the school’s headteachers and governors. Reports and ratings from Ofsted inspections are published online and are therefore available for all to read.

Ironically, the response also says: “Achieving improvements in attainment requires a partnership between the county council, school leaders, governors, parents and pupils. The transparent sharing of all school performance data will support an acceleration in the development of a self-improving system.’’

The unnamed county council official who responded to our request said: “Publishing this information is likely to have a negative impact on the credibility and trust of parents for a range of risk ratings but especially any school rated as red.”

“Releasing this information would undermine this confidential approach and compromise the in-depth discussions that are the vital next step to school improvement. School leaders understand that the risk tool might not correlate with a current Ofsted grade…a school currently judged as ‘requiring improvement’ and risk rated red could be making rapid progress and likely to be judged ‘good’ at the next inspection. These require complex explanations that would be difficult to explain in the public domain and could lead to incorrect assumptions and unhelpful conclusions with a negative impact on a school.”

As well as red, there are also amber and green ratings.

The latest ratings were issued in March – with 61 primaries (including infant/junior schools) with red ratings, 126 amber and 64 green. Nine middle schools were marked as red, with one amber. Eighteen secondary schools were red, eight amber and 12 green.

Red means a ‘significant number of groups’ at a school are ‘underachieving’. Four of those ‘red’ schools, which showed the most serious underachievement, were also sent warning notice letters.

Amber means a school is either moving in the right direction to improve – marked as ‘amber positive’ – or is moving towards a red rating and is ‘amber negative’. ‘Green’ means a vast majority of students are not under performing.

The council’s response also revealed that the rating system is “currently under review”.

The Suffolk Primary Headteachers’ Association – representing around 120 schools – launched a scathing attack on the council when the first round of ratings were issued last October. The next ratings are due to be published in September.

The council’s decision comes as there are fears Government plans to change Freedom of Information laws could place a limit on what is disclosed in the future.