A primary school has plummeted from the highest possible Ofsted rating to the lowest in less than four years.

Jolesfield Church of England Primary School in Littleworth Lane, Horsham, was inspected in June and was rated inadequate after being rated as outstanding in its last inspection in January 2010.

The school was described as “an exceptional school due to the overall effectiveness of the management, the outstanding quality of pastoral care and the excellent progress pupils make”.

Three and a half years on, the report makes for grim reading.

Leadership and management, achievement of pupils and quality of teaching all slumped to the lowest rating of inadequate while behaviour and safety of pupils rated one better - requires improvement.

It said: “For the last two years, too many pupils leaving at the end of year six have significantly underachieved because they have made inadequate progress across key stage two.”

In 2010, the school's leaders were commended for their “highly effective leadership”, and the report said: “Their consistent track record of raising standards to high levels through innovation shows that it has an excellent capacity to continue improving.”

Shortly after the previous inspection, the former headteacher and deputy headteacher entered a job-share arrangement and became co-headteachers.

Joint-headteachers Christine Knight and Sue Uff, the former being at the helm in 2010, were slammed in the latest report which said: “The school's leaders believe incorrectly that the quality of teaching is good.”

The school's chairman of governors Reverend William Harris, who too was in post for both inspections, came under scrutiny as the recent report said: “The governing body does not understand the data about the school's performance well enough to challenge school leaders robustly about it.”

In response to the report, Rev Harris said: “The whole school community at Jolesfield is keen to move the school forward, addressing the issues raised and being open about the things which did not go well.

“The leadership team, staff and governors are determined that the school will make steady and sustained improvements in order to come out of special measures as quickly as possible.”

Other shortcomings of the school indicated in the report include the poor use of teaching assistants and teachers not catering for all levels of ability.