The Government has denied claims that a prison is in "crisis" with not enough staff and half of inmates are locked up for all bar 30 minutes each day.
The Epsom Guardian was contacted by an anonymous source condemning changes at High Down Prison, in High Down Lane, on the border between Banstead and Sutton.
The source said a 'new regime' had led to 50 officers taking redundancy after being offered financial incentives last October and had caused "a huge amount of upheaval for staff".
They said that within a month the new regime had become unworkable and the 'old regime' was having to be reinstated.
A recruitment drive was started, according to the source, but newly-recruited officers were told after their first week that they were needed at other distant prisons. Many of them allegedly quit because they could not face the lengthy commute to their new postings.
The source said that at a full staff meeting on February 19, prison governors allegedly admitted the regime was "in crisis" and said the situation would not be resolved until at least the end of April.
The Epsom Guardian was also told that classes designed to reduce reoffending and to allow prisoners to secure employment upon release have been cut by 80 per cent and that in a single week, 1,400 prisoners did not attend any educational classes.
It was also claimed that half of the prison’s inmates are kept locked in their cells for 23-and-a-half hours.
The Ministry of Justice has failed to provide detailed responses to a number of the claims made by the source, but denied the prison is in crisis and said "staffing levels are at an appropriate level, with long-standing arrangements in place to fill posts using staff from other prisons if there are temporary shortages."
A spokeswoman for the Prison Service said: "We are reforming and modernising the prison estate to ensure best value for the taxpayer while also providing safe and secure prisons that deliver effective rehabilitation.
"Not only has there been a consistent reduction in prisoner-on-prisoner violence at HMP High Down, but there has also been a reduction in assaults on staff."
In response to the effect on prisoners’ rehabilitation, she said: "Operation of the prison is consistently tweaked to meet current demand and staffing levels.
"Prisoner classroom attendance and completion of qualifications is improving. HMP High Down is recognised as a high-performing prison in providing education to inmates."
The spokeswoman said it was not true that some prisoners only spend 30 minutes outside of their cells each day: "HMP High Down aims to ensure that each prisoner is out of their cell for a minimum or four hours a day between 8am and 6pm."
She said the prison’s ‘old regime’ had not been reinstated and that "there is no crisis at the prison".
The spokeswoman added: "There has been a consistent reduction in prisoner-on-prisoner violence and a reduction on assaults on staff since January 2013.
"There have also been recognised improvements in prisoner safety.
"There are appropriate staffing levels at the prison."
Do you know what is happening in High Down Prison? Contact Hardeep Matharu on the newsdesk on 020 8722 6346 or email email@example.com