Schools will be judged on how well they help pupils who are in care, as a senior Ofsted director highlighted how far they lag behind their peers in Norfolk schools.

Just 8pc of the county's looked after children last year achieved the government's 'gold standard' of five GCSEs at A*-C, including English and maths, compared to 53pc of pupils over all, according to data from the school inspectorate.

Andrew Cook, Ofsted regional director for the East of England, said inspectors will increasingly ask schools about looked after children, and their answers will increasingly influence their inspection grades.

He said: 'If we were going to test out a school, it's really good to test how they support and improve the outcomes of the most disadvantaged, as it gives an indication of how good the school is overall. If you were to measure a school on that basis, how well will your school do?'

The gap between children in care and all pupil is wider in older age groups.

In Norfolk last year, the gap was 11pc points for seven-year-olds, 36pc points for 11-year-olds, and 44pc points for 16-year-olds. This reflected a similar trend across the East of England region, and across England as a whole.

Mr Cook said: 'For me, the widening gap is really complex. Part of what we are trying to do is to see why this is happening.'

He said part of the explanation may be children going into care at a later age, but their needs should already have been on a school's radar.

Chris Snudden, head of Norfolk County Council's educational achievement service, said changes making schools more accountable for spending additional money for pupils in care would help narrow the gap.

She said: 'I think we have a long way to go. I think the circumstances are improving. I think we have to expect them to achieve in the same way as other children.'

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