Some 729 inmates in HMP Doncaster are sharing in prisoner cells built for one, new figures have revealed.
The Howard League for Penal Reform has obtained the figure as part of a national investigation into prison overcrowding - and Doncaster was named as one of the most overcrowded jails.
Frances Crook, the charity’s chief executive, said: “It should come as little surprise that such crowded conditions leave staff hugely overstretched, especially as more are being laid off.
“This means there are little to no opportunities for prisoners to work, learn or take courses to turn them away from crime.
“Staff cuts and overcrowding mean that grown men spend all weekend and up to 22 hours a day during the week cooped up like battery chickens. No wonder violence and self-injury is rife.”
But Prisons Minister Jeremy Wright said: “Let’s be clear what overcrowding in prison actually means - typically it means having to share a cell rather than having one to yourself. Prison is not somewhere that anyone should be comfortable about going back to.
“I will continue to look for ways to make the prison system more efficient and to tackle our stubbornly high reoffending rates.”