A damning National Audit Office report has confirmed the drug crisis and security failures at prisons across England and Wales – raising fresh questions about the £100 million promised to Wandsworth Prison for urgent improvements.
The government’s spending watchdog found systematic underspending on security, broken equipment left unrepaired for months or years, and a maintenance backlog that has doubled to £1.8 billion. Half of all prisoners now have a drug problem, with drone deliveries exploiting broken windows and outdated security systems.
The NAO report reveals that between 2019 and 2022, the Prison and Probation Service spent only 75% of its £100 million security investment budget – an underspend of £25 million. The largest shortfall was in gate security, where screening equipment guards against drug smuggling.
Prison governors told auditors they lack funds to fix broken security equipment. X-ray scanners for screening deliveries sit unrepaired for months. Window security improvements take years.
The age and poor condition of Victorian-era prisons like Wandsworth make them especially vulnerable to drones, which the Chief Inspector of Prisons has described as a threat to national security. Drone sightings increased by 750% between 2019 and 2023, and by 43% between 2023-24 and 2024-25.
Inmates “bend, break and burn” window grilles to allow drug deliveries, according to Tom Wheatley, president of the Prison Governors Association. The grilles are not being replaced immediately because prisons lack the budget and cannot afford to take cells out of use while the estate operates at capacity.
Maintenance backlog doubled as £47m unspent
A separate funding stream for prison maintenance and drug strategy programmes saw even worse results. Between 2022 and 2025, the service was allocated £114 million but spent only £67 million – just 69% of the budget.
Over the same period, the maintenance backlog across the prison estate doubled from £0.9 billion to £1.8 billion.
The NAO found that around half of all prisoners – approximately 40,000 people – had an identified drug problem as of April 2025. In 2024-25, prisons reported 26,348 individual drug finds, 25% more than the previous year.
Between December 2022 and December 2024, the Prisons and Probation Ombudsman investigated 833 deaths, of which 136 were drug-related.
Everything Wandsworth reported, now confirmed
The systematic failures the NAO identified match precisely what we have documented at Wandsworth Prison over the past year:
Drug crisis: The NAO found that 50% of prisoners nationally say drugs are easy to obtain. At Wandsworth in May 2024, 44% of prisoners tested positive for drugs while the Chief Inspector noted a “ubiquitous smell of cannabis.”
Broken windows: The NAO’s findings on window security taking years to fix validate the broken windows crisis that became emblematic of Wandsworth’s decline. Windows smashed to allow drone deliveries remained unrepaired for months.
Systematic neglect: MPs reported “inhumane overcrowding and filth” at Wandsworth in November 2025, echoing the NAO’s national findings on maintenance backlogs and deteriorating conditions.
Security failures: The NAO’s warnings about inadequate security equipment match the organised crime infiltration documented at Wandsworth, where a security head with criminal connections facilitated drug smuggling.
Human cost: Individual tragedies like the preventable death of Rajwinder Singh – one of seven self-inflicted deaths at Wandsworth in 12 months – illustrate the NAO’s findings that drug misuse “damages health and destabilises prison environments.”
Questions about £100m promise
The government announced in August 2024 that it would redirect £100 million to Wandsworth Prison over five years to “deliver urgent improvements” including fixing broken windows, upgrading showers, and investing in fire safety.
That promise came during the period covered by the NAO’s data showing systematic underspending on security and maintenance. The specific questions now facing the Ministry of Justice and HM Prison and Probation Service:
Has the £100 million been ring-fenced for Wandsworth specifically, or will it follow the pattern of underspending identified by the NAO?
The NAO found that between 2019-22, only 75% of security budgets were spent, and between 2022-25, only 69% of maintenance and drug strategy budgets were spent. If Wandsworth’s £100 million follows this pattern, it could mean £25-31 million never reaches the prison.
How much of the £100 million has been allocated and spent so far?
The promise was made in August 2024. Eighteen months later, the NAO report suggests systematic failures in translating funding commitments into actual security improvements. Transparency about spending to date would clarify whether Wandsworth is benefiting or whether the money remains unspent.
What oversight mechanisms exist to ensure the money is spent on the promised improvements?
The Wandsworth Prison Improvement Campaign has spent months seeking clarity on how the £100 million is being allocated. The lack of financial transparency raised in the NAO report suggests this is a systemic problem, not unique to Wandsworth.
Why does the maintenance backlog continue to grow despite allocated funding?
The doubling of the national maintenance backlog from £0.9 billion to £1.8 billion occurred during a period when maintenance budgets existed but went unspent. This pattern raises questions about whether structural problems prevent money reaching frontline improvements.
What works: wastewater testing innovation
The NAO highlighted one promising development: prisons are trialling wastewater testing to detect drug use. Rather than relying on random tests of individual prisoners – which cost £8 million annually and are operationally resource-intensive – wastewater analysis can identify drug prevalence across entire wings.
This approach provides better intelligence about where drug use is concentrated, allowing security resources to be targeted more effectively. The NAO recommended expanding this pilot programme.
How to hold the government accountable
Residents concerned about transparency and accountability around prison conditions can:
Submit a Freedom of Information request to the Ministry of Justice asking:
- How much of the £100 million promised to Wandsworth Prison has been allocated to specific improvements?
- How much has been spent to date?
- What oversight mechanisms exist to ensure full spending?
- What is the current maintenance backlog at Wandsworth specifically?
FOI requests can be submitted via the government’s FOI portal. The Ministry of Justice must respond within 20 working days.
Contact the Wandsworth Prison Improvement Campaign (WPIC), which has been monitoring conditions and advocating for transparency since 2024. WPIC can be reached via their website.
Submit evidence to the House of Commons Justice Committee, which is conducting an inquiry into rehabilitation and reducing reoffending. The committee accepts written evidence from the public. Details are available on the Parliament website.
Contact your MP – Putney’s Fleur Anderson can be reached via her constituency office or at the House of Commons.
The 16th story in an ongoing series
This is the 16th story we have written on Wandsworth Prison, which began in May 2024 when the Chief Inspector of Prisons issued an Urgent Notification describing the jail as a “pit of deaths, drugs and despair.”
Since then, we have documented every aspect of the crisis the NAO now confirms nationally: drug prevalence, broken security, maintenance failures, leadership problems, and systematic underspending.
The difference is that Wandsworth – one of the oldest and largest prisons in the UK, holding 1,500 prisoners despite being designed for fewer than 1,000 – received a specific £100 million promise. The NAO’s findings on systematic underspending make it essential to track whether that promise translates into actual improvements.
Gareth Davies, head of the National Audit Office, said:
“The proliferation of illicit drugs in prisons undermines rehabilitation, damages health, and destabilises prison environments. Yet too many of the basic controls and interventions are not being done well enough – from repairing critical security equipment to aligning health and operational priorities.”
Prisons minister Lord Timpson said: “This report exposes yet further failings in the prison system we inherited, with underinvestment in security contributing to the unacceptable levels of drugs behind bars. We are taking decisive action to grip this crisis, investing £40 million to bolster security including anti-drone measures like reinforced windows and specialist netting to keep contraband out.”
The full NAO report, “The costs of tackling drug harms in prisons,” is available on the National Audit Office website.
