Saughton Prison worst in Scotland for shared cell sizes
Some prisoners are sharing just seven square metres of personal living space
More than two thousand Scottish prisoners are living in shared cells with less than four square metres of personal living space each.
Data from the Scottish Liberal Democrats found 2,230 prisoners are sharing cells which do not meet the standard set by the Council of Europe's Committee for the Prevention of Torture.
Each prisoner should be entitled to no less than four square metres each, however 36 cells in Scotland see them sharing just seven square metres between them.
The Scottish Government says this is not legally binding, and in many cases the living space is only marginally below this level.
Less than four square metres of personal living space each
Most of the problem cells are found in Edinburgh’s Saughton Prison.
Lib Dem justice spokesman Liam McArthur said: "On the SNP's watch, not only are prisons bursting at the seams, but the conditions inside many of them contravene basic standards for humane treatment.
"The problem is so acute that the Government's best justification is that most cells are only 'marginally smaller' than the internationally-recognised minimum standards.
"In a number of cases though, the Government are failing even to achieve the low standard that they've set themselves here.
"Cells are only 'marginally smaller'"
"As well as posing threats to staff safety, this overcrowding makes it much harder for prison staff to focus on successful rehabilitation that is key to reducing reoffending."
In November, the Lib Dems received a response from the chief executive of the Scottish Prison Service, Teresa Medhurst, through a parliamentary question, detailing the numbers of two-prisoner cells where there is a living space of less than four square metres.
Ms Medhurst said: "Whilst the Council of Prevention of Torture's minimum standard for personal living space in prison establishments for multiple occupancy cells is four metres squared plus fully-partitioned sanitary facility, not complying with this standard does not constitute a breach of the law."
A Scottish Prison Service spokeswoman said: "The health and wellbeing of all those who live in our establishments is a key priority and our staff work hard to ensure their rights and needs are met.
Health and wellbeing of prisoners is "a key priority"
"However, we have a population that is rapidly increasing, and far more complex, due to factors such as types of offending, levels of serious and organised crime, a growing older population, and high numbers of remand prisoners.
"Many of our establishments are full beyond their design capacity and this increases the pressure on the space available."
A Scottish Government spokesman said: "The safety and wellbeing of everyone in the prison estate is a priority for us and the Scottish Prison Service and we are taking action in relation to the high and increasingly complex prison population.
"Despite an autumn statement that ministers have made clear was devastating for Scottish finances, we are increasing investment in our vital prison service by increasing the SPS resource budget by 10% to £38.5 million.
"The additional funding for SPS is a crucial component of that, enabling them to continue to provide a safe and secure prison system.
"£167 million capital funding will be invested in the prison estate to allow SPS to progress the construction of HMP Highland and HMP Glasgow, continuing the modernisation of the prison estate to better meet the needs of staff and prisoners."