HMP Wandsworth is the most overcrowded prison in the country, official data shows.
The scandal-hit jail holds 62 per cent more people than its design capacity, Ministry of Justice figures show.
One of the UK’s largest prisons, Wandsworth currently houses 1,444 inmates against a design capacity of 894.
Conditions inside the Category B prison have been described as “inhumane”.
The chaos at the south-west London prison has been laid bare through a series of high-profile incidents, exacerbated by overcrowding.
According to the Howard League for Penal Reform, Category B prisons tend to be the most overcrowded, with a “constantly churning population”.
Prisons accommodate the excess by cramming two inmates into single cells, or three into cells intended for only two.
According to the latest available figures from March, Wandsworth is closely followed by HMP Leeds (61% more prisoners than it is designed for), and HMP Durham (59%).
In September 2023, former soldier Daniel Khalife, later found guilty of spying for Iran, escaped from the prison by clinging to the underside of a food delivery truck.
He was caught on a canal towpath by a plainclothes detective days later.
The mistaken release of Algerian national Brahim Kaddour-Cherif put HMP Wandsworth back in the headlines last year.
Also in 2025, former Wandsworth prison officer Linda De Sousa Abreu was jailed for 15 months after having sex with an inmate in a cell.
Footage of the activity was widely shared on social media.
The prison was put into special measures in 2024 as one of 10 jails issued with an urgent notice to improve since November 2022.
Inspectors said the turmoil they found was the result of “sustained decline permitted to happen in plain view of leaders”, and prison guards did not always know where prisoners on their wings were, despite an investment of almost £900,000 since the escape.
But in the latest review of the prison in April last year, the watchdog noted a new governor has brought “energy and focus” and was prioritising safety and decency.
Inspectors found “substantial investment” in staffing and training but overall level of experience was low.
In October, a further report by the prisons independent monitoring board found staffing was a recurrent problem, with an average of a third of staff absent a day.
It also found that living conditions in the crumbling 170-year-old building were “unacceptable” and “inhumane”.
A Ministry of Justice spokesperson said: “We are investing hundreds of millions of pounds to build more prison places and improve conditions to fix the broken justice system, while strengthening community sentences to deliver punishment that works to cut crime.”
