One of Northampton's biggest schools has lost its "outstanding" rating in its latest Ofsted report after inspectors fond teaching standards were "too variable" across the board.
The watchdog carried out an inspection for the Berrywood Road school on November 8 and 9 this year, observing 29 lessons and conducting 10 short visits to classes.
But despite finding many areas of strength, Ofsted has downgraded the school to "requires improvement," the second-lowest of four possible ratings.
The report, released today, states: "The quality of teaching requires improvement, as it is too variable across the school.
"Owing to this, teaching does not enable all groups of pupils to make good or better progress across a range of subjects."
And it goes on to say: "Where learning is less effective, teachers’ expectations of their pupils are not high enough.
"They do not plan work that meets the needs of the individual pupils. Teachers do not ask pupils effective questions to assess the level of their understanding."
Since the last Ofsted inspection in 2014, the school has left the Academies Enterprise Trust.
It became an all-through school in September 2015, with its pupils now ranging from the ages of four to 18.
The report pays particular attention to the quality of leadership at the school, which it says is starting to improve.
It states: "Until recently, leaders at all levels had not taken sufficient action to maintain the high quality of the school’s provision identified at the last inspection.
"The new leadership team, however, is now taking appropriate action to develop a culture of higher expectations, particularly of pupils’ achievement."
However, the report goes on to say: "These actions have not ensured that pupils’ progress, while now improving, is strong across all subject areas in each year group."
Inspectors praised the work of the Sixth Form, judging it ‘good’ overall.
The work of the Primary School was also praised as good overall.
Speaking on behalf of the school, Chair of The Duston Education Trust Ros Clayton, said: "What is made very clear throughout the whole of our inspection report is that our school has many strengths.
"We are pleased that inspectors recognised that we knew the areas of our work we needed to develop, were already robustly addressing these, and that pupils’ outcomes across Key Stage 3 and 4 had already improved. This Ofsted report gives a strong basis for moving forward."
Last month the Chronicle & Echo reported how the National Union of Teachers had concerns about the welfare of staff at The Duston School after its members reported a spate of resignations there.
The previous head Jane Herriman left mid-term in May in order to "pursue other opportunities."