The redevelopment of a Victorian wing at Nottingham Prison has been delayed due to a funding shortfall, a prison watchdog claims.
The prison's B wing was shut down in 2005 because it was "unfit for use".
The Independent Monitoring Board's Julian Ellis said his sources indicated a lack of money meant it would not be replaced for at least a year.
The Home Office said there were currently no plans to re-open the wing, but a feasibility study was under way.
The Independent Monitoring Board has recommended that the old Victorian B wing be demolished and replaced by a new building.
Mr Ellis said the prison was overcrowded and needed upgrading, adding: "The Treasury is not providing enough money to do the job properly."
The disused B-wing originally accommodated 250 inmates.
Chief Inspector of Prisons Ann Owers said in a report that the B-wing was not fit to be used.