The Scottish Government has announced a wholesale review of sentencing and prison policy amid worsening overcrowding and delays and cost over-runs for new jails. 

SNP justice secretary Angeala Constance said the externally-led exercise would be an in-depth look at how best to deal with offending behaviour.

The last long-range review was delivered in July 2008 by a commission led by former Scottish Labour First Minister Henry McLeish.

It recommended a cut in prisoner numbers from 8,000 to 5,000 with jail reserved for the most serious offenders, fewer short-term sentences and more community payback schemes.

Although many of its proposals were accepted and implemented under the SNP, the prison population remains at around 8,000 today.

Updating MSPs on the latest figures - an average daily prison population of 7,959 last week - Ms Constance said she had no plans to release prisoners early to relieve overcrowding.

However she did announce an independent review intended to lead to “less crime and fewer victims”. 

It will examine “how and when custodial sentences and community interventions are used”, how effective these are and what more can be done to prevent crime and cut reoffending.

Ms Constance said: “Protecting victims and the public from harm is my absolute priority and prison will always be necessary as part of that. 

“However, we must recognise that, while appropriate in many cases, short prison sentences are often not the best way to reduce reoffending, with those released from short custodial sentences reconvicted nearly twice as often as those sentenced to a community payback order.

“Therefore an externally led review of sentencing and penal policy will allow us to revisit the fundamental question of how imprisonment and community-based sentences are used. 

We must do more to develop community interventions with increased breadth and depth, so that the courts have a greater selection of options to deal robustly and constructively with the individuals before them.

“The prison population in Scotland remains too high and the needs of those in prison are increasingly complex. 

“While a range of work is underway to respond to this, we also need to understand and address its root causes. The aim of this review is not about reducing the prison population as an end in itself, but ensuring that custody is used for the right people at the right time.”

Tory MSP Russell Findlay asked why the Government had failed to build HMP Glasgow, the replacement for the city’s Barlinnie jail, was years late and budgeted at £400m.

Ms Constance said the Government could not build its way out of the problem, but later confirmed the government remained committed to HMP Barlinnie.

She said ministers had no choice but to complete the project - Barlinnie holds 1 in 8 of Scotland’s prisoners - even though the costs were significant. 

Phil Fairlie, Assistant Secretary of the Prison Officers Association said: "Every day our members are having to deal with the record number of prisoners crammed into Scotland’s prisons, with some regularly operating above their safe capacity. 

“When we add chronic drug use, widespread mental health issues, the influence of organised crime groups and increasing violence and self-harm, we have a very challenging and potentially dangerous environment for all within it.

"Our plea on this issue is not for more prisons, it is for fewer prisoners. 

“The POA will always work with the Scottish Prison Service and the Scottish Government to address overcrowding in our prisons but this either requires a radical change in sentencing policy in this country, or a significant investment in staffing and the prison estate. 

“It cannot be done on the cheap or by maintaining the status quo”.