HMP Hewell 'dirty and dangerous'
The performance of a Worcestershire prison has deteriorated sharply in the three years since its previous inspection, a report said.
It added inspectors found HMP Hewell was unacceptably dirty, there were high levels of assaults and some staff appeared to lack motivation.
The inspection in November 2012 identified "significant concerns", the HM Inspectorate of Prisons report said.
The jail said "decisive action" had been taken.
Chief Inspector of Prisons Nick Hardwick said much of the jail "provided an unsafe and degrading environment".
He said: "Managers at a local and national level need to be very clear that the current level of performance is not acceptable, and ensure that effective and robust action is taken."
HM Inspectorate of Prisons said 35% of prisoners on the closed side and 42% on the open side said it was easy to get drugs, which was much higher than in comparable jails.
There had been 94 reported prisoner-on-prisoner assaults at the closed site in six months before the inspection, which was significantly higher than at other similar jails, the report said.
But the inspectorate also said prisoners were generally positive about relations with staff, disciplinary processes were generally well managed and the quality of learning, skills and work activities was good.
The National Offender Management Service, on behalf of the prison, said the jail had been through a significant period of restructuring and change.
The service's chief executive officer, Michael Spurr, said: "At the time of the inspection the prison's performance was below acceptable standards although the new governor was working hard to address the deficiencies.
"Since the inspection we have strengthened the management team."
Andrew Neilson, director of campaigns at the Howard League for Penal Reform charity, said: "This is a damning report into a dirty, dangerous and drug-ridden prison, where cleaning materials are difficult to get hold of, but alcohol is readily available."