The study finds that those in care are more prone to "go missing" as local authorities are under no legal obligation to tell other authorities if they place a child in foster care in another area.

The emphasis on school league tables has also led to some schools refusing to accept children whom they perceive as disruptive or less likely to do well academically.

The report calls on the government to examine ways of promoting a more vocational curriculum to reduce drop-out rates among less academic pupils and for a greater focus on welfare-based intervention for children with special educational needs.

Warning against punitive approaches to tackling truancy, Nacro director of education and employment Craig Harris said: "If we are to tackle problems of attendance, education provision should be more relevant to the needs and abilities of all children, regardless of whether they are academically suited of gifted practically."

Nacro also highlights the link between disaffection at school and future offending. Of young people referred to youth offending teams, 41 per cent had truanted regularly prior to coming into contact with the youth justice system and more than half were identified as having special educational needs.

Children miss school for a wide variety of reasons including low attainment and bullying. They sometimes drop out of the system without trace for up to two years.

- Missing Out from 020 7840 6427.