CARDINAL Newman High School topped the tables for the highest performing school in Warrington after 96 per cent of students achieved five A* to C grades in their GCSEs in 2013.
Yet the school was told by Ofsted inspectors that it requires improvement just months later.
Teaching unions across the country have criticised Ofsted for putting up increasingly difficult hurdles for schools to jump over to hit the top ratings.
A collection of schools - despite churning out record-breaking results - are being flagged up by Ofsted as needing to improve.
Cardinal Newman High School in Latchford was visited by inspectors in December where the school’s governing body fell under scrutiny from inspectors for not having an ‘accurate enough view of students’ achievement’.
But despite receiving the second lowest grading available to Ofsted inspectors, 68 per cent of pupils achieved five A* to C grades including English and maths, which was a record for the school.
The school was also judged good for achievement, quality of teaching and behaviour and safety of pupils by Ofsted inspectors but was still given the low rating.
Julie Warburton, head of school, said: “Our success is due to the consistently high standards expected of students, both academically and in their behaviour and personal presentation.
“Personalised curriculum pathways which meet the needs and aspirations of each individual and a rich array of extra-curricular opportunities help to prepare our students for the world beyond Cardinal Newman.”
National executive member for NASUWT for Merseyside and Cheshire, Mick Burrows, criticised Ofsted for regularly moving the goal posts.
He said: “We get a lot of reports of where one inspector says one thing, and another says something totally contradictory.
“Teachers and schools don't know what to do for the best, and it's creating panic and confusion.
“Teachers have to concentrate more on second-guessing what Ofsted will think rather than on what is right for their students.”
Mr Burrows also accused the Government of having ulterior motives for failing schools.
He added: “There is evidence that schools are failing Ofsted inspections as a softening-up exercise to push them into becoming an academy.”
A council spokesman added: “The proportion of schools judged inadequate in Warrington, at two per cent, is better than that found nationally at three per cent.
“The proportion of Warrington schools judged as outstanding at 23 per cent is better than that found nationally at 20 per cent.
“We continue to believe in the strength of the Warrington family of schools and by working together we achieve more for our children.”
An Ofsted spokesman said it was committed to improving schools so that children across the north west have the best possible opportunity of receiving a good education.
“From time to time we make changes to the way we inspect – such as introducing the requires improvement judgement – to ensure that we are challenging schools to be the best they can be.
“To ensure teachers and school leaders know exactly what to expect during an inspection we publish all of the relevant documents on our website.
“This includes the framework for inspection, a handbook for inspectors and regular additional guidance to provide updates where necessary.”