Inmates "spend too long in their cells" with not enough “purposeful activity”, according to a report on one of Kent's prisons.

Chief inspector of prisons Anne Owers visited Swaleside Prison on the Isle of Sheppey earlier this year and a report of her findings has been published.

She said that although there were good relationships between prisoners and staff, more than 40 per cent of inmates were locked up during the day and better management of learning and skills was needed.

She pointed out that the prison had to deal with a "challenging population of serious offenders".

According to her report, arrangements to prevent bullying and self-harm were good and prisoners said they felt significantly safer than they did at other prisons.

It described staff-prisoner relationships as a "particular strength" and said there was an effective personal officer scheme, although black and minority ethnic prisoners were more negative about the prison than white inmates.

Ms Owers pointed out that the use of illegal drugs was a problem - but that the prison was working hard to reduce both the supply and demand.

She said although the environment was generally good, prisoners’ self-catering areas were a "health hazard".

The report said health services were adequate but that prisoners complained about the attitude of health care staff.

Ms Owers noted there was reluctance among some staff to “modernise and develop” services.

She said arrangements to manage the arrival of prisoners was satisfactory although the reception was poorly designed.

The report highlighted several areas for improvement including addressing the negative perception of treatment among black and minority ethnic prisoners, looking at the “negative staff culture” among healthcare staff, prisoners should spend less time in their cells, there should be enough activities to occupy prisoners, and inmates should have more access to education and vocational training.

Ms Owers said: "Swaleside has to manage a challenging population of serious offenders and it is therefore commendable that we found it to be a very safe prison.

"It was pleasing to find that staff-prisoner relationships remained extremely good.

"The clustering of the three Sheppey prisons had led to some improvements in resettlement, but cluster managers had failed to ensure that there was sufficient purposeful activity and prisoners spent too long in their cells.

"This weakness needs to be addressed if Swaleside is to become a first-rate prison."