Plans to axe 1,000 jobs in the Education Department and halve the number of sites under radical cost-saving measures have been coming under increasing attack.
Union leaders and politicians criticised Education Secretary Michael Gove, warning he was "playing politics" with people's lives.
The department has been conducting a review over the past year, which has proposed saving £290 million by 2015/16 and reducing its workforce in England by a quarter, affecting jobs in human resources, finance and computing.
The number of sites will be cut from 12 to six, generating savings of around £15 million a year, while spending on IT will be reduced "considerably."
Union leaders believe other Government departments will come under pressure to follow suit if the cuts go through as planned.
Mark Serwotka, general secretary of the Public and Commercial Services union, said: "Michael Gove appears to want to run the education department as some kind of nightmarish right-wing experiment, playing politics with people's livelihoods and putting at risk the very important services DfE civil servants provide to teachers and the public."
Shadow Education Secretary Stephen Twigg said: "Last week the Education select committee warned that children's policy was in danger of withering. Now these leaked plans make no mention of children's policies - services like Sure Start and support for vulnerable children or those in care. It focuses exclusively on academies and free schools. Policies must be based on what families want, not out-of-touch ministers."
A Department for Education spokesman said: "The Permanent Secretary commissioned a review to make sure we have the capability to deliver well-designed policies that have a real, measurable impact on the children and young people who need it most, while minimising costs to the taxpayer. The review found that the Department has committed and hard-working staff producing high quality work, but that we can and should work more effectively and efficiently.
"Over the coming months we will target our staff time and money on only our top priorities, cutting red tape and concentrating on the work that adds the most value. We are reducing the size of our backroom staff (eg HR, finance and IT) and merging offices to reduce the cost of our buildings.
"The DfE had already committed to reducing its administrative budget in real terms by 42% from 2010-11 to 2014-15. Following the review, our target is a 50% reduction to £290 million by 2015-16 and we have already achieved over half of these savings."