Local authorities have made more than 1,000 school improvement staff redundant since last autumn, prompting fears that more schools could end up in special measures as a result.
Aspect, the union for children's services workers, says it has been notified of 1,031 job losses so far; two-thirds of those affected were employed under the National Strategies school improvement programme, which ends later this month.
Hundreds more jobs are expected to go as many more councils announce redundancies over the next 12 months. Aspect has warned that the end of the strategies, coupled with swingeing local authority cuts, is leading councils to dismantle whole departments devoted to school improvement.
Many deprived areas, which are suffering disproportionately from cuts to area-specific grants, will be worst hit, the union says.
Aspect general secretary John Chowcat told The TES: "Clearly, the number of job losses among school improvement and effectiveness officers and others is going to carry on increasing. Some councils are taking out some very senior layers of staff.
"Restructuring will mean some departments becoming traded services, but their further activity will depend on the income they attract.
"There is still a lot of demand for these services, particularly in primary schools, but future jobs depend on how council services compete in the marketplace."
Russell Hobby, general secretary of heads' union the NAHT, said headteachers were seeing support services "disappearing before their very eyes".
"A real concern is that we will be left with very small local authority teams looking at the data and thinking that converting a school to academy status is a quick-fix solution, when it is not," he warned.
But the fragmentation of school support services will not be universally mourned.
Sir Michael Wilshaw, celebrated head of Mossbourne Academy in Hackney, east London, told a conference recently that the National Strategies took good staff out of schools.
Many heads and teachers have complained about the heavy-handed approach some local authorities have taken towards school improvement in recent years - regarding the offer of support as an unnecessary and sometimes professionally insulting imposition.
John Bangs, former head of education at the NUT and a research associate at Cambridge University, said: "The implications of all this - dismantling National Strategies, getting rid of school improvement partners, reducing local authority support services - are enormous.
"There will now be a very uneven approach to school improvement; standards will go down and an increase in schools going into special measures."
He said that the schools which were most in need of help were those least likely to ask for it.
TUC RALLY - On the march
Hundreds of teachers and education workers are expected to be among a crowd of up to 200,000 people attending a demonstration in London against Government cuts on 26 March.
Organiser the TUC has arranged the event for three days after the Budget to promote alternatives to cutting public services. The march will start on the Embankment and end in a rally in Hyde Park.
The TUC has been in close contact with the Metropolitan Police in a bid to ensure there is no repeat of the controversial "kettling" techniques used in the student riots before Christmas.
- Original headline: Union warnings as LA support role `disappears' amid job cuts