A Wellingborough primary school has lost its good rating after Ofsted found a drop in reading, writing and math standards and a 'variable' quality of teaching.
All Saints Primary School and Nursery requires improvements in its effectiveness of leadership and management; the quality of its teaching, learning and assessment and in its outcomes for pupils.
It did score a good rating in the personal development, behaviour and welfare category and for its early years provision.
Inspectors noted standards in reading, writing and maths declined over recent years for pupils leaving key stage 2.
"Leaders and the governing body have not acted swiftly enough to halt this trend," said lead inspector Peter Stonier.
"Too many pupils, including disadvantaged pupils and pupils who have special educational needs (SEN) and/or disabilities, do not make good progress during their time in key stage 2."
The report described the quality of teaching as 'variable', adding that staff did not consistently use pupils' assessment information effectively to "challenge the most able pupils and to support the least able pupils".
Rates of absence and persistent absence were above the national averages.
All Saints headteacher Emma Johnson said: "We are disappointed with the findings of Ofsted which are centred around our key stage 2 data.
"We had a one-day inspection in April which highlighted many positives, leaving us with a target area around data.
"With only 70 days to work on this, it was always going to be a challenge to show impact, however, the report does highlight the positive steps that the school and leadership team have taken towards this area."
The school's strengths include children getting off to "a flying start" in the early years and making good progress throughout key stage 1.
Pupils are described as polite and well-behaved and that incidents of low-level disruption and bullying are "extremely rare".
"We have experienced some challenges with staff changes and spent time embedding our behaviour policy which was an area that was recognised as good by the inspection team," said Mrs Johnson.
"The governors and staff are all committed to driving forward to improve the outcomes for the key stage 2 children whilst continuing to ensure that All Saints provides the best possible education for all.
"Parents have been very supportive and we are certain that when Ofsted returns within 30 months the school will gain at least good across all areas."
The full report can be found on Ofsted's website.
In 2016, the school was rated outstanding after a statutory inspection of Anglican and Methodist schools by the Church of England's education office.