Irthlingborough's Huxlow Science College has been branded inadequate after a damning report which found racist language there was commonplace.
The Finedon Road secondary school has been heavily criticised by Ofsted, who dropped its rating from good to the lowest possible after a two-day inspection.
In a report highly critical of behaviour, education watchdog inspectors found that many pupils feel unsafe, that many are not confident that staff take bullying seriously and that safeguarding arrangements are not effective.
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Paul Letch, headteacher of Huxlow Science College, said: “Since joining Huxlow Science College as headteacher in September we quickly identified a number of areas that needed improving rapidly, particularly the general behaviour of a minority of pupils.
“Our comprehensive improvement plan is already being implemented and we are pleased that Ofsted inspectors recognised the positive impact some of these changes have made and that parents, pupils and staff have confidence in these plans.
“Ofsted’s comments reflect our own observations, and we agree that we need to continue and accelerate these changes to bring about these improvements in behaviour and standards across the college.
“We have valued the recent and ongoing support of the leadership team at Hatton Academies Trust and Sir Christopher Hatton Academy, who we have been working closely with to make these rapid improvements.”
The report by Jayne Ashman, Ofsted's lead inspector, gave Huxlow Science College individual grades of inadequate in three of the five areas judged, with the other two found to require improvement.
It said: "There are failings in the safeguarding culture of the school. Too many pupils are victims of inappropriate sexual behaviour or harassment.
"Too many pupils do not trust that bullying, including racist, sexist and homophobic bullying, will be effectively resolved. Leaders and governors must establish a culture of openness and respect."
The report added that poor behaviour has hindered learning at times and that staff do not have consistently high expectations of what pupils can achieve.
It said: "Many pupils feel unsafe in school because of the poor behaviour of others. Many pupils reported feeling uneasy around school and some say that they feel intimidated.
"Racist, sexist and homophobic language is commonplace. Girls report that the behaviour of boys sometimes makes them feel unsafe."
The inspection report also found that pupils are not prepared well for life in modern Britain. It said they have little understanding of other faiths, religions and cultures.
One pupil summed up the views of many when he said: "Pupils here need to know more about other cultures. They need educating. They are ignorant of the world outside of the school gates."
Ofsted's report also said that pupils do not know enough about healthy relationships, consent or respect, adding that some do not respect those who are of a different sexual orientation, gender or ethnicity.
But they added that new leaders have had a positive impact and that recent action has been taken to improve the school.
The report said: "The staff, parents and carers, and pupils said that they had confidence in the new headteacher. They said that his leadership was making a positive difference."