Prisons inspector says overcrowded Barlinnie is unsafe
Scotland's largest prison, Barlinnie in Glasgow, is more than 50% over capacity, with about 500 inmates more than it is designed for.
Brigadier Hugh Monro, the chief inspector of prisons, said this meant it could not be regarded as "safe".
He has called for more investment and a review of the management of overall prisoner numbers.
In particular he wants a review of why so many men who have not yet faced a trial are held in Barlinnie.
In his inspection report, Brig Monro said the number of remand prisoners at Barlinnie had risen by 28% since 2009, compared to an increase of just 5% in the overall prison population.
He said this increase had contributed to the overcrowding at the prison, which mainly caters for short-term prisoners from the Glasgow area.
At the time of his inspection, in May, there were 1,477 men in Barlinnie, which has a design capacity of 1,018.
By November, the number held had risen to 1,565, more than 50% over capacity.
Brig Monro said this meant the jail was not as safe as it should be.
He said the churn of prisoners coming through the gates made it difficult to offer meaningful education, work or health programmes to help prevent them from reoffending.
"The prison has an operational limit for very good reasons," he said.
"It's about staff to prisoner ratios; it's about how prisoners can be searched when you're moving them about; it's about prisoners sharing cells which should be for only one man."
He was particularly critical of the health centre at the prison and the educational facilities with only three classrooms - smaller than that at Inverness Prison which caters for about 150.
The chief inspector's report said the opening of the new Low Moss prison in East Dunbartonshire in 2012 would reduce pressure, by creating 700 new places - but Brig Monro said money must nevertheless be spent urgently at Barlinnie.
The Scottish Prison Service (SPS) is looking at ways of upgrading Barlinnie - but its building budget has been cut by the Scottish government by 68%.
Barlinnie's governor, Derek McGill, said there was nothing he could do about overcrowding as he must house all prisoners sent there by the courts.
But he said he was concerned at the increase in the number of remand prisoners.
"I think they are going up because there is an element of risk required to leave somebody in the community, and perhaps the judges are not as disposed to leave people in the community," he said.
"Perhaps they would rather take less risk and remand them."
But he revealed SPS was looking at plans to refurbish Barlinnie's education unit and reception area which have been criticised in several inspection reports.
He said overall the inspection report was positive, and recognised the prison was well led and run.
But he added: "If we could eliminate overcrowding, we could do more with the prisoners."