EXCLUSIVE: Three prisons are nearly half empty, while a further six are more than a quarter empty amid a capacity crisis.
Kier Starmer has released nearly 40,000 prisoners while several prisons are nearly half empty (Image: Getty)
Several prisons in the UK are nearly half empty despite the ongoing capacity crisis that saw Labour release nearly 40,000 prisoners early. Conservative shadow justice minister Kieran Mullan has said “it’s an insult to victims and puts the public at increased risk” and that the “Labour Government needs to grip this issue”.
The Ministry of Justice (MoJ) claims “this is not true” and that all male prisons are at “over 80% capacity”, but their own population figures tell a different story. When looking at the baseline certified normal accommodation (CNA) for prisons – the sum total of all certified accommodation in a prison – two prisons are less than half full and a further seven are more than a quarter empty.
HMP Cookham Wood in Rochester, Kent, is certified to house 180 prisoners, but there were just 83 inmates there in October. This is 46% of its certified capacity. When looking at the ‘In Use CNA’ figures for the prison, which accounts for cells not for immediate use due to damage or renovations, there are 166 cells currently available in the prison – exactly half of those are filled by the 83 inmates in the Category C adult male prison.
Inside HMP Cookham Wood: Just 83 of the 180 certified places are filled (Image: Getty)
Despite having these 166 cells available for use, the prison is listed to have an operational capacity of just 84. The MoJ say this is based on levels of “control, security and the proper operation of the planned regime” which is largely affected by staffing. It is by this metric the MoJ claims the prison is at 98.8% capacity, despite half of the prison’s usable cells being empty.
Kieran Mullan said: “It can be that there is a mismatch between types of spaces available and types of prisoners. But this government is releasing criminals early onto our streets.
“This should be a final option of last resort. Even if it means moving prisoners away from home. Public safety should come first. Not the rights and wishes of criminals.”
Then Justice Secretary Shabana Mahmood opened Millsike Prison this March. Now it’s nearly half empty (Image: Danny Lawson/PA Wire)
There is a situation at the next least filled adult male prison, Millsike in East Yorkshire, also a Category C and Britain’s newest prison, which opened in March this year. Just 53.9% of its baseline CNA of 1,468 places was filled by 787 convicts in October – up from September’s figure of 48.9%. What’s worse here is that all of Millsike’s brand-new 1,468 spaces are currently listed as ready to use, but its operational capacity is listed at just 834 spaces. By this figure, the prison is listed to be 94.4% full when nearly half of its usable cells sit empty.
However, an MoJ spokesperson did point out that Labour has delivered around 2,600 prison places since the election in July 2024. This follows a period during which only 500 net places were added to the estate between May 2010 and July 2024.
Unconvinced, Mr Mullan said: “We [Conservatives] will be bringing forward proposals to reform prison building in this country-but right now the Labour Government needs to grip this issue and stop blaming everybody else for problems getting worse on their watch.”
He said: “Not only have we seen this huge spike in mistakes but the new proposals from Labour don’t exclude violent and sexual offenders as other early releases. That really is unprecedented. It’s an insult to victims and puts the public at increased risk.”
“We have since seen a drop in prison officers in the year after Labour came in. This is only going to make it even more difficult to manage our prisons and keep prisoners inside where they belong,” he added.
There are nine prisons and young offenders institutions which are below 75% full according to baseline statistics. Adult male prisons Kirklevington Grange (in North Yorkshire), Millsike and Cookham Wood are all below 60% full and Young Offenders Institution Wetherby (in West Yorkshire) is at just 30.5%. See our interactive map below.
Some of these figures can be attributed to the poor state of the cells, rendering them currently unusable. However, this explanation cannot be used for all of them. The MoJ figures show that for five of these prisons, the vast majority of their cells are in a fit state for use. However, for all five of these prisons, at least a quarter of the cells are empty. In some, as many as half of them are not occupied.
The five prisons that fall in this category are: Cookham Wood, Millbank, Askham Grange women’s prison (in North Yorkshire), and Werrington (in Staffordshire) and Wetherby – both young offenders institutions.
The MoJ spokesperson maintained that the department is “refurbishing old and dilapidated cells as well as building four new prisons to address the demand for prison places and make prison more effective at cutting crime.”
£4.7 billion has been allocated towards delivering 14,000 places by Justice Secretary David Lammy. By 2032, £7 billion will have been invested to build 14,000 new operational prison places.
| Prison name | Baseline CNA (total cells not including those damaged) | Population | Percentage full | Category |
| Wetherby | 318 | 97 | 30.50% | Young offenders institution |
| Cookham Wood | 180 | 83 | 46.10% | Category C adult male |
| Millsike | 1,468 | 787 | 53.60% | Category C adult male |
| Kirklevington Grange | 327 | 192 | 58.70% | Category D adult male |
| East Sutton Park | 137 | 87 | 63.50% | Category D open prison and YOI for women aged 18+ |
| Askham Grange | 128 | 82 | 64.10% | Category D open prison for women |
| Werrington | 118 | 81 | 68.60% | Young offenders institution |
| Liverpool | 1,128 | 785 | 69.50% | Category B adult male |
| Sudbury | 755 | 547 | 72.50% |
Source: MoJ prison population figures October 2025
