Swansea Council has been condemned for "naive" informal agreements to protect children from abuse, according to a leaked report seen by BBC Wales.
These include asking a parent with a history of domestic violence and alcohol misuse to sign an agreement not to drink while caring for them.
The council told BBC Dragon's Eye it has stopped using the agreements.
Meanwhile, ministers are set to intervene next week in the running of the council's children's services.
It follows two critical reports into its child protection procedures.
The Dragon's Eye programme has learnt that a formal announcement will be made next week, after a deadline for improvement was set up ministers.
An intervention board will be put in place under the first such order made against a council in Wales.
Last week, deputy social services minister Gwenda Thomas told AMs she was not prepared for social services for children to fall and remain below acceptable standards.
She believes Swansea has failed to make sufficient progress to tackle the issues identified by an inspection in 2007 and make the necessary improvements.
A critical report from 2007 demanded that the council stop the practice of non-binding written agreements with parents to protect children, as well as grading several children's services as "poor".
The new draft report to be published next month will say there have been clear improvements since 2007 - none of the services are any longer described as "poor" and some are considered to be "mainly good".
But the report highlights several services where the performance is inconsistent.
Tthe Care and Social Services Inspectorate Wales (CSSIW) report will say: "Of particular concern to inspectors was the continuing, inappropriate use within the authority of 'child protection' or 'safe care' agreements."
The report cites two cases discovered by inspectors:
A family known to social services for some years because of ongoing neglect, physical and emotional abuse.
Assessments were undertaken but child protection procedures have never been invoked.
The parent has been hostile and uncooperative. Instead of a professional, multi agency approach, an agreement was drawn up where the parent agreed not to physically chastise the child other than a smack on the bottom if absolutely necessary.
Inspectors said no other way of parenting or controlling the child seemed to have been offered.
A family with a history of domestic violence and alcohol misuse dating back some years.
Two referrals were received last year - one of a child playing with dangerous material which had been left around while the parent was asleep and a second of the child's parent being drunk and unable to care for the child, who became ill.
Medical assistance was called for, and the medical staff were concerned about the parent's drunken state.
Referrals were made but no child protection procedures were put in place. Instead the inspectors say a "naïve" child protection agreement was drawn up in which the parent, who acknowledges a drinking problem, agreed not to drink alcohol whilst caring for the children.
A Swansea Council spokesman said its priority was to ensure that children were safe.
"Thanks to the commitment of our staff and the support of the CSSIW we have been able to start the improvements that need to occur and some progress has been achieved," said the spokesman.
"The council recognises that resources are important and there is a commitment to maintain investment.
"We welcome the fact that the deputy minister has recognised the commitment of our staff and the improvements we have started. However, she wants to be more confident they are effectively embedded and long lasting.
"We share her determination and we recognise there is much more to do to sustain and develop the improvements CSSIW have identified."
It said it would work over the coming months to meet the challenges and deliver the services expected by vulnerable children and their families and a "constructive debate" with the deputy minister had started.
A full response would be given once the report had been published.
It is understood the assembly government will make an order under Section 84 of the Children Act 1989 declaring Swansea council in default of certain of its functions in relation to the provision of children's social services.
A statement is likely next Tuesday.
The intervention board will include a chair drawn from outside social services and local government, a current or past director of social services, a local authority chief executive and an elected councillor with experience in social services matters.
It would have the power to oversee the department and ensure it improved.
Dragon's Eye is broadcast at 2235 GMT on Thursday on BBC One Wales.