The government has an "appalling" lack of understanding of the growing pressure on England's child-protection services, a spending watchdog says, according to the BBC.
The National Audit Office pointed to a huge rise in demand since 2010.
Council budgets had been cut by nearly 30% over this period, it said, and 91% of local authorities were now overspending on children's services.
The Department for Education said it was working to improve its understanding of the growing pressures.
The NAO report, Pressures on Children's Social Care, said the number of children taken into care had trebled over the period, once population growth had been accounted for.
And the number of child-protection assessments made by local authorities had risen by 77%.
Overall, local authorities were planning to spend £350m, or 9%, more in 2018-19 than they had budgeted for during the previous financial year, the NAO said.
Meg Hillier, who chairs the Commons Public Accounts Committee, which scrutinises NAO reports, said: "With an overspend of £872m last year on children's social care and with local government under such funding pressure, government has got to grasp the nettle.
"Children's safety and wellbeing must not be subject to a postcode lottery and it is appalling that the department does not fully understand what is driving demand for children's social care or why there are such wide variations between local authorities."
One of the key pressures on children's services since 2010 has been the rise in the number of the most serious and expensive cases - children taken into care.
Read the rest of the BBC report here.