Part of HM Nottingham Prison needs to be closed and urgently refurbished, independent watchdogs have said.
The Home Secretary will decide if repairs go ahead
The Independent Monitoring Board (IMB) has published its annual assessment of conditions at the Perry Road site.
It said the worn-out Victorian wing is becoming totally unsuitable for accommodating anybody - especially in winter when it can be as cold as 10C.
Prison governor Wendy Sinclair agreed there are problems, but said conditions are getting better.
'Enough is enough'
Julian Ellis, of the IMB team, said the Chief Inspector of Prisons had visited the jail earlier this year and hoped the subsequent report would back up their requests for improvement.
"The Prison Service has now said that this money should be available as soon as the new wing opens at Nottingham Prison later this year, but we will believe it when we see it."
He added: "The situation is slowly deteriorating.
"Successive governors of the prison have all been requesting the money - but one of the points of having an independent monitoring board like this is that we have the power of publicity... so that we can make a fuss and finally say, as we have today, 'enough is enough'".
The report also raises serious concerns over the state of some toilets in shared cells.
The IMB said no work has been carried out to screen them off, leading to the "unacceptably degrading" treatment of prisoners.
But the document also acknowledges that significant improvements have been made in helping prisoners return to outside life, and reducing self harm incidents by 60%.
The annual report is sent to the Home Secretary who will decide on what action to take.