A flagship city school has slipped into special measures for the second time in just over five years, the Mail can reveal.

Endeavour High School, in Beverley Road, was recently visited by Ofsted inspectors, who have concluded it is making inadequate progress in raising achievement and standards.

The report is yet to be published but the Mail understands staff at the school and the local education authority dispute the findings.

Although they said they could not comment until the report is made public, it is understood they will appeal the decision.

Ofsted places schools in special measures when it considers they fail to supply an acceptable level of education and appear to lack the leadership necessary to improve.

Endeavour will now be given an action plan by inspectors and the school will face more monitoring visits.

A source close to the school said it was "peculiar" inspectors had come to the conclusion it should be placed special measures, especially in light of an Ofsted monitoring report in November which highlighted highly "innovative" practices put in place to demonstrate progress.

The source, who refused to be named, said the report also contains conflicting evidence.

They said: "It is not a report of a school in special measures, it is incredibly positive about a number of things such as the care, guidance and support given to pupils and the curriculum.

"No teaching was judged unsatisfactory, yet teaching and learning was inadequate.

"The report says the school has a safe environment, behaviour is satisfactory and bullying is not regarded as an issue.

"But overall, the school has been found to be inadequate on progress.

"What the school has not been given is the opportunity to take into account the results at Key Stage Three and GCSE, which will be public knowledge in two month's time.

Endeavour was made the subject of a notice to improve in March last year.

Inspectors asked the school at the time to improve achievement and raise standards, including attendance and students' rate of progress.

Inspectors then made a monitoring visit in November and said it was making satisfactory progress and praised systems in place for making that progress.