Last month, 2,164 inmates were on remand, among them 303 who were convicted but awaiting sentence, bringing the total remand population to 29 per cent.

Howard League Scotland said the Scottish rates were “unfathomable”.

In April 2020, the remand figure was 1,114. This rose to 2,000 by September of that year. Of those on remand, 33 per cent have been waiting more than 140 days.

The 140-day rule was once the “jewel in the crown” of the Scottish criminal justice system because of its guarantee of justice without undue delay. In 2015, Scottish Legal News reported that the rule was being routinely ignored. That trend has not abated.

Liam McArthur, Liberal Democrat MSP, said: “The SNP needs to tackle lengthy court delays … We need proper investment in bail supervision orders and electronic tagging so that remand is only used where it is necessary to safeguard communities and public safety.”

A spokesman for the Scottish Prison Service said: “We are managing an increasingly complex prison population. Certain demographics are unable to be located in certain establishments, or even in the same area within an establishment. The challenge we face on remand is also exacerbated by the court backlog, where it is routinely in excess of 140 days.”

A Scottish government spokeswoman said: “The Bail and Release from Custody Bill is currently before parliament, and seeks to refocus how custody can be used within the criminal justice system to ensure public safety is protected.

“The Scottish government has invested an additional £3.2 million this year towards strengthening alternatives to remand, including further expansion of bail supervision.”