Prisoners around the country are being "cooped up like battery hens" and HMP Wandsworth has been named as the worst of all, according to new figures

An analysis by the Howard League for Penal Reform say that 1,102 of Wandsworth's 1,496 prisoners are being held in overcrowded cells.

Frances Crook, chief executive of the Howard League for Penal Reform, said this was leading to an increase in violence.

“Wandsworth is under immense strain, with violence and self-injury rising and more prisoners being held in overcrowded cells than in any other jail in the country," he said.

“Keeping men cooped up like battery hens is never going to help them to lead crime-free lives on release.

“This is a challenge for the new Secretary of State for Justice, who now has a chance to build a positive legacy.

"Bold action to reduce the number of people behind bars would not only ease pressure on the prisons; it would save lives, protect staff and prevent crime.”

Other jails with particularly high numbers of prisoners in overcrowded cells include G4S-run Oakwood (916), Leeds (786), Durham (785), Sodexo-run Forest Bank (739), Serco-run Doncaster (695), G4S-run Altcourse (686), Serco-run Thameside (596), Preston (517), Hull (511), Birmingham (484), Pentonville (483), Elmley (447), Cardiff (444), Bullingdon (397) and Exeter (375).

Mr Crook added that most prisoners living in overcrowded conditions are required to share cells that were designed for one person. A smaller number may be forced to sleep three to a cell, in cells meant for two.