Given the condition of Scotland’s prisons in general, the Scottish government and the SPS must also develop robust contingency plans in case any other part of the prison estate becomes uninhabitable.

All contingency plans should reflect the immediate capacity issues faced by the SPS and the fact that there is no evidence to suggest that prisoner numbers will decrease in the short term.

In a report published today, the committee said 10 years of capital underspend to stay within budget should have raised serious concerns at an early stage given the deteriorating state of prisons.

Jenny Marra MSP, convener of the Public Audit Committee, said: “Audit Scotland says HMP Barlinnie presents the ‘biggest risk of failure in the prison system’ but warns there is no clear contingency plan for accommodating the 1,460 prisoners it currently holds should it fail.

“Developing a contingency plan for Barlinnie in the event that it fails must be of the highest priority. Given the state of prisons generally, the Scottish government and the SPS must develop robust contingency plans should any other part of the prison estate become uninhabitable.”

On underlying pressure on the prison service, Ms Marra added: “It is clear to the committee that there are significant and wide-ranging challenges both the SPS and Scottish government must overcome. The SPS is currently accommodating around 500 prisoners above capacity and there is no evidence to suggest that prisoner numbers will decrease in the short term.

“At the same time, the SPS’s revenue budget is down by 12.5 per cent in real terms; the capital programmes for HMPs Barlinnie, Inverness and Greenock are behind schedule and prisoner violence is on the increase. At its core, this situation is undermining the Scottish government’s policy objectives of rehabilitating prisoners and reducing re-offending.”