Conditions at Nottingham prison have been criticised in a new report.
The report says more funds are needed
It says 60% of inmates at the prison are sharing cells meant for one person and there are not enough resources to deal with them.
The report raises concerns about the handling of people with mental health problems.
The number of prisoners went up to 550 in November.
The Board of Visitors in its Annual Report says resources have not kept pace with the growing number of inmates.
That means there has been no extra health care laid on, no extra work opportunities and most significantly no additional staff.
While some extra short term funding has been provided, cash is needed in the longer term to improve accommodation.
The report also says there is an increasing number of inmates with mental health problems who should not be sent to prison as an alternative to treatment outside.
But the report goes on to congratulate staff who have managed to achieve performance improvements, despite population and budget pressures.