The Government is playing Russian roulette with public safety and the criminal justice system is heading for meltdown, the Prison Officers' Association warned.
Riots like the one which saw Ford open prison near Arundel, West Sussex, go up in flames at the start of the year show how "sometimes risk management to save a few pounds backfires spectacularly", the POA's general secretary Steve Gillan said.
"Under a Labour government year-on-year savings have cut uniformed staff to the bone and now the coalition Government is playing Russian roulette with safety," he said.
"The criminal justice system is heading for meltdown."
His warning, in the POA members' magazine Gatelodge, follows concerns over staffing levels and the type of offenders being held in open prisons after about 40 offenders took control of Ford prison, smashing windows and setting fire to buildings on New Year's Day.
"The criminal justice system is heading for meltdown if the coalition Government cuts are realised over the spending review period," Mr Gillan said.
"The POA does not wish to sound alarmist, but the health and safety of prison officers, prisoners and the general public is being placed in danger by ill-thought-out policies that have not been tested nor, in my view, have any justification or foundation.
"Privatisation and payment by results seem to be the chosen path, but they are doomed to failure."
Prison officers were being "assaulted on a daily basis", he said.
"This union is not looking for conflict with any political party.
"However, if you ignore the warning signs and place POA members' health and safety in danger in the name of the cuts, then as a trade union we will not stand by and allow that to happen.
"Unfortunately when unemployment has risen in the past, crime has also risen. So cuts to policing, housing and to the NHS will blend into one and have a detrimental effect on society as a whole."
The violence at Ford started after guards attempted to breathalyse inmates for contraband alcohol in the early hours, it is understood.
During the early stages of the rebellion, just two officers and four support staff were on duty, at a centre which holds around 500 inmates.
The guards were forced to retreat as the violence increased. Scores of riot police and specialist prison officers were brought in before authorities eventually regained control.
Rioters caused extensive damage to six accommodation blocks, a gym, mail room and snooker and pool rooms.
It also emerged that the Independent Monitoring Board (IMB) warned Prison Service officials about the staffing problems and the lack of proper control overnight at Ford just days before the riot.
The IMB report noted that in the past three years since the introduction of a dog handler with two dogs, a large amount of contraband has been discovered including 360 mobile phones, 323 chargers, 115 SIM cards, £1,221 of cash, 200 items of drug paraphernalia, 11 parcels and 51 litres of alcohol.
Writing in Gatelodge, Mark Freeman, the POA's deputy general secretary, added: "No lessons had been learned from previous reports and warnings regarding alcohol and the wrong type of prisoners being held there.
"Staff were placed in an intolerable position and were extremely lucky not to have been seriously injured by flawed policies and the Prison Service lacking the resolve to resist sending the wrong prisoners to Ford.
"It is patently obvious to a blind man on a galloping horse that six staff, only two of whom were fully trained, cannot safely contain 496 prisoners and should never again be expected to."
A Prison Service spokesman said: "Prisons are secure and ordered environments housing a complex and challenging population.
"Incidents are dealt with professionally and efficiently by trained Prison Service staff.
"We take the safety of our staff and security within our prisons very seriously.
"Staffing levels across the prisons estate are strictly risk-assessed and there is a zero tolerance approach to violence against staff.
"Incidents such as those at HMP Ford are thankfully rare but do demonstrate the difficult challenges that prison staff face and it is to their credit that prison regimes are peaceful and well-ordered."
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