Liverpool Prison officers have staged a walkout in protest at the "unjust sacking" of a colleague.
The Prison Officers Association (POA) said the officer, who has 26 years of service, was cleared of any wrongdoing by police after an investigation into an incident with an inmate.
Staff say they fear for their personal safety and accused local management of refusing to provide them with any assurances.
Leaders of the POA said: "Prison officers face ever-increasing levels of violence due to the unprecedented levels of drugs and debt within the prison population, and Liverpool is a high-risk prison. "Prison officers are taught to use control and restraint to manage the prison population. As part of the training they are taught to use a pre-emptive strike if they feel their personal safety, that of a colleague or a prisoner is at risk.
"The officer used this approved method and was unjustly sacked.
"Prison officers now fear they will lose their jobs if they use force and will often allow prisoners to assault them rather than risk their employment."