Nearly two thirds of prisons in England and Wales are operating at an overcrowded level, reformers say.
There are 7,294 more people in the system than it is designed and built to hold, according to an analysis of prison population statistics by the Prison Reform Trust.
Although the growth in the prison population has slowed down in recent months, 77 out of 131 establishments were over the Prison Service's Certified Normal Accommodation (CNA) as of July 27, the trust said.
CNA is "the good, decent standard of accommodation that the service aspires to provide all prisoners", a trust spokesman added.
The most overcrowded prison in England and Wales, according to official figures, is HMP Kennet in Liverpool, Merseyside, the spokesman said.
Designed to hold 175 men, it now holds 337. In second place is Shrewsbury (built to hold 170 men, it holds 326) and third is Swansea (built for 240, it holds 436).
The spokesman said: "For people in prison themselves, overcrowding has a tangible impact. Figures for 2010/11 show that nearly a quarter of people in prison are being held in overcrowded accommodation, either doubling up in cells designed for one occupant or being held three to a cell in cells designed for two people.
"Private prisons have held a higher percentage of their prisoners in overcrowded accommodation than public sector prisons every year for the 13 years to 2010/11.
"Overcrowding makes it much harder for staff to work intensively with offenders on resettlement.
"Currently 47 per cent of adults reoffend within a year of leaving prison, rising to almost 57 per cent for those who had served a sentence of less than 12 months. Nearly 70 per cent of children (10-17) released from custody reoffend within a year."
Juliet Lyon, director of the trust, said: "Building our way out of the overcrowding problem is not the answer. The prison population can be safely reduced by curbing inflation in sentencing, calling a halt to any unnecessary use of custodial remand, dealing with addictions and investing in effective community penalties.
"Court ordered community sentences are more effective, by eight percentage points, at reducing one-year proven reoffending rates than custodial sentences of less than 12 months for similar offences. Rather than falling back on short, ineffective spells behind bars, investment in more intensive community sentences and public health solutions would cut crime and save the taxpayer money."
A Prison Service spokeswoman said: "All of our prisons provide acceptable levels of accommodation for prisoners, although some prisons hold more people than they were originally designed for.
"We are aiming to reduce the existence of crowding alongside reducing the cost of the prison estate."
26 August 2011
27 October 2011
30 January 2012