Child protection services are far too important to be exposed to the "fickleness and failings" of private sector organisations, according to a group of academics.
Almost 40 senior social services academics, led by Professor Ray Jones, of Kingston University, have signed a letter published in The Guardian expressing their concern that children's social work services in England, including child protection, could be "opened up to the market and without regulation".
A Department for Education consultation paper published last month says that enabling local authorities to outsource children's social services will encourage innovation and improve outcomes for at-risk youngsters, the Guardian reported.
The newspaper said the document asserts that private providers will allow authorities to "harness third-party expertise" and "stimulate new approaches to securing improvements" for safeguarding services outside "traditional hierarchies".
In their letter, the 37 academics wrote: "England has one of the most successful child protection systems in the world. This is based on strong accountability, stability, continuity, good local partnership working across professionals and agencies, and with experienced and committed professionals and leadership.
"The intention that private sector organisations such as G4S, Serco, Atos and others should be able to run child protection services causes considerable concern.
"Their track record elsewhere has hardly been unblemished in providing Olympics security, over-claiming payments for tagging offenders, misreporting on GP out-of hours contracts, and delaying and denying disability benefits."
They add: "Child protection is much too important to be exposed to their fickleness and failings."
A spokeswoman at the Department for Education said: "We want to improve the quality and efficiency of children's social care.
"Some councils are already using external expertise to improve their work, while others have asked us to extend these freedoms so that they can look at new, improved ways of delivering services.
"There will be no obligation for councils to take up these freedoms and any that do will still be held accountable by Ofsted. We will take into account all responses to the consultation before setting out next steps."