Half of the £8.6bn children’s services budget in England is spent on 73,000 young people in the care system, research by the Institute for Fiscal Studies (IFS) has shown.

Despite public spending on children being maintained over the past 20 years, 72% of budgets are now spent on those in severe need.

The research into the levels of government spending in this area was commissioned by the Children’s Commissioner ahead of next year’s spending review.

The report, Public Spending on Children in England: 2000 to 2020, shows that spending on children from the main government departments – excluding healthcare where data is limited – was over £120bn or £10,000 per child under 18.

The report showed there has been a reorientation of spending towards statutory help for children in crisis, while overall children’s services spending has been largely frozen since 2009–10.

Other findings in the report include growing pressures on ‘high needs’ education budgets, as more children are now attending specialist high-needs institutions. The numbers of pupils in maintained special schools increased by 25% between 2007 and 2017, outstripping overall pupil growth.

The increase is largely driven by a rise in the numbers of children with autism in maintained special schools (up more than 50% between 2012 and 2017), along with rises in pupils with severe learning difficulties and speech, language and communication needs.

Anne Longfield, the Children’s Commissioner for England, said: ‘This analysis shows that while overall public spending on children has been broadly maintained over the last 20 years, millions of vulnerable children who are not entitled to statutory support will be missing out because of the huge cost of helping a small number of children who are in crisis.

‘While every child should receive the support they need, the economic and social costs of this current strategy are unsustainable.

‘I hope this analysis will help to move the debate on from one simply about the amount we spend on children, to a debate about how we spend it.’