A massive rise in the number of academies and free schools means the education system is "sleepwalking into centralisation," teaching unions warned on Monday.
The Local Government Information Unit (LGiU), acting on behalf of the National Union of Teachers (NUT) and Unison, interviewed heads of academy chains, leading academic commentators and other experts to assess the impact of this transformation.
It found concerns that up to 24,000 schools could be managed from a single Whitehall department and that conversions to academies are creating gaps in accountability, admissions monitoring, schools support services and place planning.
Christine Blower, general secretary of the NUT, said: "The NUT has long championed the vital role of local authorities in education but recognises that successive changes to the system have fatally undermined their strategic role. It would be a shocking waste of expertise and resources to limit the role of local government still further."
Unison national secretary, for education and children's services Jon Richards added: "The rapid increase in the number of academies and reduced funding has seen key local authority roles, such as performance management and school improvement, diminished.
"These losses and the changing responsibility for admissions, which ought to be geographic and even-handed, will inevitably lead to an incoherent education system, undermining good government policies on access and social mobility."