Guards at one of Britain's toughest jails should be given stab vests and pepper spray following a series of attacks on inmates and staff, the Prison Officers' Association has said
The union is lobbying the Prison Service to issue workers at Frankland in County Durham with the protective gear to wear on routine duties.
However the Prison Service has said that knife-proof vests could increase the likelihood of attacks.
Staff at the maximum security jail currently undertake day-to-day duties with only a baton for protection.
"It's one of the highest security prisons and holds the worst type of prisoners," said Tom Robson, vice chairman of the Prison Officers' Association.
"We look after some of the most dangerous people in British society," he added.
"It has everything from mass murderers to terrorism and those convicted of drugs extortion and sex crimes.
"There are frequent assaults on prison officers, some serious, some less serious. There are also prisoner-to-prisoner assaults and staff are injured intervening.
"Our best weapon will always be our ability to talk to people but we'd like to have as much protection as possible."
The call comes after child rapist Mitchell Harrison, 23, who was serving a life sentence, was murdered and disembowelled in his cell at Frankland.
Michael Parr, 32, has pleaded guilty to murder and is yet to be sentenced.
The jail has also housed some of Britain's most notorious killers, including Charles Bronson, Ian Huntley and Harold Shipman, and has a significant number of inmates serving life sentences.
A Prison Service spokesman said current safety measures were adequate.
She said: "We take the responsibility of keeping staff, prisoners and visitors safe extremely seriously.
"That's why we have a violence management system in place to deal with incidents quickly and robustly, with serious incidents referred to the police immediately.
"Stab vests are issued to prison staff where appropriate. The decision not to issue them to all staff is kept under review as part of our commitment to reduce violence in prisons."