According to staff at the seventeenth-century castle prison, the smuggling of drugs and alcohol through visits is 'out of control'.
Prison officers are also concerned about the high level of violence and bullying between inmates which, officers claim, is drug-related.
Prison officers blame low staffing levels at the overcrowded jail - which holds around 250 prisoners - for inadequate supervision of visits and lack of searches.
Staff concerns are outlined in a report on the jail, by Judge Stephen Tumim, the Chief Inspector of Prisons, who recommends that visitors no longer be allowed to bring in food and drink, even when the refreshment kiosk, usually run by the Women's Royal Voluntary Service, is closed.
Lancaster prison was due to close, and the historic castle returned to the local authority and the Duchy of Lancaster, but overcrowding and forecasts of an even higher prison population, mean it will remain a jail.
Judge Tumim said: 'That Lancaster continued to function was a triumph of improvisation. Staff readily accepted that the only way this over- crowded prison could operate was to establish sound relationships with inmates, and make the best use of the poor living and working environment which both groups shared.'
He said inmates seemed to have improvised their own routine. 'Thus on both days of the inspection, while those who wished to go to work did so, other prisoners either basked in the sun on the exercise yard or remained in their living units.'
Yesterday, the Prison Service said that since Judge Tumim's inspection last June, an anti-bullying policy and additional security at visiting times had been implemented.Reuse content