One in four prisons is cutting back on education as the Government's tough-on-crime policies are set to expand the jail population by 15,000, the Home Office has admitted.
Some prisons are making "severe cutbacks" in teaching as a three-year programme of budget reductions across the service begins to bite, according to senior sources.
Among those seeking savings in education is Pentonville Prison in London, where a fifth of teaching hours are set to be lost.
The Home Office admission will come as an acute embarrassment for ministers in the week when the Learmont Inquiry into the Parkhurst Prison escape earlier this year uncovered "a chapter of errors at every level and a naivety that defies belief".
The beleaguered Home Secretary Michael Howard is to be quizzed on the state of prison teaching next week by shadow home office minister George Howarth.
Confirmation of fears that inmate education would represent a "soft target" for governors under pressure to slash spending has caused alarm among prisoner welfare groups.
The Prison Reform Trust, whose own latest research confirms evidence of increasing cuts in many jails, emphasised the central importance of education and training in the rehabilitation process.
The Learmont Inquiry report identifies major flaws in leadership, operations and security, and sets out a series of recommendations including a multimillion pound spending package, mainly directed at security improvements.
The recommendations have yet to be considered by the Home Office, but will inevitably result in increased pressure on prison budgets already being slashed by 8.6 per cent over three years to 1999.
Revelations of the extent of education cuts will only add to pressures on the Home Secretary, already facing criticism over allegedly failing to make clear the extent of his involvement in running the Prison Service.
A spokesman for the service admitted around a quarter of prisons were saving on teaching, but described the national picture as mixed, with other governors managing to keep budgets steady and some increasing investment.
However, Nick Flynn, Prison Reform Trust deputy director, said research into the place of education within prison regimes for a forthcoming report had also highlighted widespread reductions in spending on the service.
He said: "We are seeing an ever-increasing population causing a massive drain on limited resources. In terms of priorities, education will tend to suffer. "
New and costly demands such as compulsory drug testing of prisoners were syphoning cash from education, he said. Education co-ordinators had reported reductions in staffing and teaching hours, frequently with very little notice, allowing no time to plan cuts. "It was just a case of axeing courses there and then. It caused turmoil for the curriculum but also stress and low morale for people involved in delivering it."
Because teaching staff are employed via a contract with a college or other provider, cutting their hours is seen as less sensitive than making redundancies among prison officers. One senior prison manager said: "Eighty per cent of the budget goes on pay. You cannot cut electricity, water and other basic utilities - therefore the only flexible things are those like education. You are looking at a soft target."
The Prison Officers Association, concerned at the increasing pressures on governors to spend on security and calling for more investment in members' training, also supports spending on inmate education as a crucial element of rehabilitation.
"Education is a crucial contributory factor in the atmosphere of a prison, which in turn has implications for safety," said a POA spokesman.