Norfolk County Council has triggered a little-known legal procedure in an attempt to stop parents knowing how it rates Norfolk schools.

For three years, it has assessed future risks to all schools and academies that could stop them receiving a 'good' judgement at their next Ofsted inspection.

The system places them in three broad categories - causing concern, requiring improvement, or a potential system leader - and in its assessment at the start of this academic year, 72 fell into the bottom category, 119 in the middle, and 231 in the top.

However, the council has refused to say which school is in which band.

In November, it turned down an EDP Freedom of Information request asking for this information, and a month later rejected an appeal, arguing it would make it less likely schools would share data with it, damaging its work to support education in the county.

The EDP argued parents should be able to see the most recent assessments about their schools, especially as many Ofsted report are several years old.

In January, Cliff Jordan, leader of the Conservative councillors, and now leader of Norfolk County Council, said: 'Parents up and down our county have a right to know whether their local school is in good shape or not. Sadly, this is typical of the secret-squirrel tactics employed by the current council leadership.'

Last month, the Information Commissioner's Office ruled it was in the public interest for the ratings to be released.

It said: 'In the commissioners's view, disclosure is unlikely either to have a significant effect on the willingness of schools to contribute to the process carried out by the council, or else any inhibition caused to the free and frank manner with which advice is provided or views are exchanged would not be sufficiently severe, extensive or frequent to prejudice the council's work in this area.'

However, council solicitors have now launched an appeal to the First-Tier Tribunal in an attempt to overturn the decision - the first time it has done so, according to the Courts and Tribunals Service website.

In its submission, it argued: 'The Information Commissioner, in its decision, failed to grasp the impact upon the parties, school performance and morale of disclosing this information to the press.'

It claimed the decision was inconsistent with previous rulings, and warned of 'probable sensationalisation and manipulation of the information'. It had previously criticised coverage of risk ratings of Suffolk schools by the BBC and the East Anglian Daily Times.

A council spokesman said: 'We are appealing this decision because in this case we believe the Information Commissioner did not appreciate the extent to which the disclosure of our risk assessments of the achievement of Norfolk schools would prejudice or be likely to prejudice the effective conduct of public affairs.

'It is our view that releasing this information would diminish the championing work of the council. Disclosure of the dialogue that we have with individual schools to ensure children and young people are receiving the best possible education would undo the good work already done. Without this dialogue, our existing approach – that has contributed to significant improvements in Norfolk's schools – would be invalidated.

'Our view is shared by schools who responded to a survey we conducted. Of the 195 replies we received in two days, 181 – or 95pc - felt disclosure of the information would be prejudicial to the working arrangement between the council and schools.'