Judge Stephen Tumim, the Chief Inspector of Prisons, said it was 'unacceptable' that a lack of nursing staff meant these prisoners were being supervised by discipline staff in cramped, unsanitary conditions.
Although the prison was built to hold 555 prisoners, when Judge Tumim's staff visited, the jail was holding more than 1,000. The overcrowding, and lack of facilities and activities, mean that most of the jail's unconvicted prisoners were forced to spend up to 21 hours locked in their cells. Some had only one shower a week and insufficient changes of clothes.
Judge Tumim praised the staff's efforts, despite the difficulties and training described as 'abysmal'.
The report was greeted with dismay by prison reform groups. 'It is a humanitarian outrage that so many mentally disturbed people should be held in such grossly unsuitable conditions,' said Vivien Stern, director of the National Association for the Care and Resettlement of Offenders.
'The report underlines the need to ensure the speedy assessment and care of mentally disordered people by the health service, rather than in the prison system.'
Yesterday the Home Office accepted that Winson Green's overcrowding was unacceptable and pointed out that new prisons would shortly be opened to take the overspill. Kenneth Clarke, the Home Secretary, said in a statement that arrangements had been made at nearby prisons to take some of the jail's mentally disordered prisoners. Prison medical officers had been reminded of the need to identify those needing hospital care and arrange their transfer.
But Ms Stern said she was disappointed that the Home Secretary's response to conditions that were 'an affront to a civilised society' was to open new prisons.
'These will not relieve overcrowding if they are simply filled up with ever increasing numbers of additional prisoners,' she said. 'The pressure on prisons like Winson Green will only be reduced if this country reduces its readiness to imprison many offenders who pose no danger to the public.'