Unions representing staff at Wandsworth Prison have rejected a report by the Chief Inspector of Prisons accusing some officers of ruling through a 'climate of fear'.

Sir David Ramsbotham found the approach of some prison officers at the south London jail - one of Britain's biggest - to be "callous and uncaring." Others were guilty of intimidation, racism and sexism.

The prison officers' union claims he exaggerated the conditions he had found.

But Sir David told BBC Radio 4's Today programme: "This is not something that has grown up overnight, this has been there for years. The Prison Service know about it, their management know about it, people in the prison know about it and nobody has done anything about it."

Wandsworth has been given a year to make radical improvements or face the threat of privatisation.

Prisons minister Paul Boateng said: "While I accept the view of the chief inspector and the director general that the situation at Wandsworth is not comparable to that which existed at Wormwood Scrubs, Wandsworth clearly has an attitude problem.

"This prison is not performing acceptably and must improve."

Filth of 'Wandsworth Way'

In his inspection report Sir David said he never wanted to see again the conditions and treatment of prisoners that were evident during his inspection, comprising what he called "The Wandsworth Way".

"Never have I had to write about anything so inhuman and reprehensible as the way that prisoners, some of them seeking protection and some of them mentally disordered, were treated in the filthy and untidy segregation unit," said the report.

Inspectors discovered cockroaches in two cells, and dead rats in the exercise yard.

Almost one in seven of the jail's 1,295 inmates said they had been assaulted by staff.

One inmate said officers held him down and used him as "a punchbag". Many said they were simply too scared to lodge official complaints.

There was also a nasty undertone of racism and sexism to some staff attitudes, the report said.

Inmates were humiliated during strip searches, had haphazard access to showers and exercise.

Treatment towards prisoners ranged from "at best off hand and at worst menacing and threatening".

Cells were filthy and stank of urine and some of the in-cell toilets were broken, inspectors said.

Treatment of foreign nationals was "at best thoroughly inadequate", and the treatment of families of prisoners was sometimes "despicable", the report added.

'Wandsworth not brutal'

Prison unions accused Sir David of going to Wandsworth with preconceived ideas about what he would find, and of lacking evidence for his claims.

A subsequent report by Cambridge University had found, for instance, that only 4% of prisoners had been assaulted by staff.

Mark Healey of the Prison Officers Association, said budget cuts at a time of increased numbers of prisoners had also added to the pressures on staff.

But Sir David said it was "impossible" to judge a prison before seeing it, and that conditions were "measured as carefully as we possibly can".

He added that the culture of the prison - where only one officer has been suspended - must be changed.

Prison Service Director General Martin Narey said he accepted some of Sir David's criticism, but pointed out that the prison had an "excellent" drugs programme and that many staff were "pleasant, courteous and helpful".

He said he "would not tolerate" the abuse of prisoners, and that work had already begun to improve conditions at the jail.

"It is being dealt with. It is not a matter of prisoners being brutalised,

"But I accept that prisoners are sometimes not treated with the respect and dignity they deserve, and I won't tolerate that," he added.