Low Moss prison in Bishopbriggs is set to close in three months time, it has emerged.
Low Moss prison was built as a wartime RAF camp
The news has led to claims that other Scottish jails will end up with increased overcrowding.
A new prison is to be built at Low Moss, but is unlikely to be ready for at least two years.
The Scottish Prison Service (SPS) said overcrowding problems were being overcome with the construction of new wings at Glenochil and Perth prisons.
Low Moss is a medium security prison with space for up to 300 inmates.
Beginning life as a wartime RAF camp, it was the subject of a critical report in 2005 by the prison inspectorate which slammed "entirely unsuitable" old dormitories.
The SPS said the prison will close on 28 May.
In a statement it said: "The decision to close HMP Low Moss follows the outcome of the SPS Estates Review in 2002.
"It is SPS intention, subject to planning conditions, that a new prison be built on the existing site."
A spokesman was unable to say when the new prison would be ready but agreed it could be two years or more.
He denied the closure would put undue pressure on the rest of the system and added that Low Moss took prisoners from other establishments rather than receiving them directly from the courts.
He said the announcement would enable advance work to begin for the new jail, and end uncertainty for the staff.
"Our assessment is that we can minimise the impact of closure," he said.
The Scottish National Party claimed that closing Low Moss now would cause chaos, claiming Scottish jails were already bursting at the seams.
The party's justice spokesman Kenny MacAskill said: "Having less cells when we have ever more convicted criminals is a dangerous situation that threatens prison security.
"The Labour and Lib Dem government's prison policy was in turmoil but it's now in chaos.
"Inadequate as Low Moss may be, closing it puts further pressure on an already overcrowded prison system which is already bursting at the seams."
The prison service said men normally sent to Low Moss could be housed instead in new accommodation at other prisons.
Low Moss' closure follows a controversial review of Scotland's prison capacity in 2002.
That resulted a decision to build a new private prison at Addiewell in West Lothian and a second prison on the site of Low Moss, for which the public and private sector would compete.
East Dunbartonshire Council rejected plans for the £100m, 700-cell replacement prison, but last month the Scottish Executive gave the scheme the go-ahead provided certain conditions were met.
These included the Scottish Prison Service making a contribution to the council for its transport strategy for the A803 route.