The entire governing body of a special school in Wilburton resigned ahead of an Ofsted inspection that concluded it was inadequate in all five key areas.

The report into The Harbour -that caters for 74 boys with social, emotional and mental health needs - also touched on how often the school uses physical restraint to control unruly students.

"Records of governors' meetings indicate that governors have been asking leaders challenging questions about the use of restraint," says Ofsted's lead inspector Caroline Pardy.

"As a result there has been a decline in the number of pupil restraints. However the number of behaviour incidents remains high."

She said the former governors "have not been rigorous in ensuring that the necessary actions are followed through in order to improve aspects of the school's work".

Ms Pardy said: "Governors recently reviewed their effectiveness and decided the school would benefit from a new governing body.

"As a result all of the governors have resigned. The local authority has taken swift action to put in place an interim executive board to take on the role of school governance."

Ms Pardy also warned that The Harbour needed to take "urgent action to ensure that pupils' liberty is not restricted in the school."

Ofsted found many classroom doors were locked as a "behaviour management strategy" but this restricts pupils' liberty.

Ms Pardy's team concluded that leadership, management, quality of teaching, learning, behaviour and welfare of pupils and outcomes for pupils were all inadequate.

"Leadership is weak and ineffective and leaders have an inaccurate and overinflated view of the school's effectiveness," she said. "They have not taken effective action to make necessary improvement; as a result there has been a decline in the standard of provision."

Ofsted also found pupils' safety was being put at risk on a daily basis and noted that nothing had been done about an uncovered pond that is easily accessed by pupils.

"Leaders are aware of the potential risk it presents but have not taken appropriate action to make the area safe," said Ofsted. "Pupils are also able to leave the school site because it is not secure."

The school was criticised for not sustaining improvements that were visible during a monitoring inspection two years ago and for not establishing acceptable behaviour.

"A third of staff who expressed a view felt senior staff did not support them when dealing with pupils' misbehaviour," says Ofsted.

Teachers were criticised on a number of fronts ranging from 'weak' teaching of reading and writing to producing work for pupils that "lacks challenge".

On behaviour and welfare, Ofsted says over a third of staff felt pupils were not safe at The Harbour.

"Pupils are potentially at risk because leaders have not ensured that staff follows agreed policies and procedures," says the report. "Potential hazards are not carefully risk assessed or made safe."

The school has a high number of temporary staff, says Ofsted, some who are not trained or qualified to meet the needs of the pupils. "This places the welfare of the pupils potentially risk," says the report.

Bullying is also covered in the report with one in four pupils who completed an Ofsted questionnaire of the opinion that the school did not deal with it effectively.

Ofsted felt the "behaviour of pupils is inadequate" and that "attendance remains well below average" whilst the number of fixed-term exclusions, whilst reducing, remains "too high".

Ofsted concluded that pupils have poor attitudes to learning because teaching does not meet their needs.

Expectations of pupils' achievements and behaviour are too low and pupils make too little progress in improving their writing.

"The curriculum does not provide pupils with the knowledge and skills they need in order to be successful," says the report. "The heads of English and mathematics do not have enough impact on improving their subjects. They have limited knowledge of provision outside their own key stage."

On school strengths, Ofsted noted that procedures relating to those pupils on the child protection register are rigorous and those in the nurture unit make good academic and social progress.

Key stage 4 pupils who attended college gain suitable qualifications, says Ofsted and progress in maths is improving.

Ofsted inspected the school on March 28-29 and also considered responses from 31 staff and 17 pupils.

"There were too few parental responses to our online questionnaire parent view for analysis," says Ofsted.