The Independent Monitoring Boards says conditions at Wandsworth reflect the failures of the prison system as a whole.
The IMB says there has been no real progress in resolving problems caused by years of underinvestment in the fabric, facilities and staff.
The report says violence levels continue to rise and assaults rose by over 20% in all areas during the monitoring period.
It also says that conditions remain inhumane, with serious overcrowding in Victorian buildings where the fabric continues to deteriorate.
Published today, it looked at the timeframe between June last year and May this year.
This was before the alleged escape of former soldier Daniel Khalife from the Victorian jail in September.
IMB Chair, Tim Aikens, said:
“Recent events at Wandsworth have demonstrated the shortcomings of the prison system that the IMB has been highlighting repeatedly for many years. Prisoners are being failed and most have a severely reduced chance of rehabilitation upon release. We are told there is significant investment in the prison system, but we see little evidence of this in Wandsworth.”
A Prison Service spokesperson says it has taken “decisive action” to address the “serious issues” raised and has increased frontline staffing.