The council said it was taking “immediate action”
Child protection services in Cumbria have been described as “inadequate”, by Ofsted inspectors.
The watchdog’s report said a number of children were not “adequately protected” and social workers needed “better supervision”.
However, inspectors noted there had been “positive changes” since the last inspection and staff were “committed”.
Cumbria County Council admitted it was unacceptable for children to be at “risk” because of “poor practice”.
Ofsted inspectors said social workers must “get better” at listening to children and act more quickly where they are not being properly looked after by their parents or carers.
Julia Morrison, director of children’s services at the council, said: “I accept Ofsted’s findings; it is simply not acceptable for children to be left at risk because of poor practice.
“I am encouraged that Ofsted recognised the work that we have done since the last inspection and share their view that the pace of change must increase.”
The council said it was taking “immediate action” to improve the issues raised by Ofsted.