Inmates are too frightened to leave their cells at Swaleside prison which has been blasted following an unannounced inspection.

A report, published today by HM Inspectorate of Prisons, also found arrangements for Muslim prisoners - including Friday prayers - mean other inmates face restrictions, and suicide and self-harm prevention measures are inadequate.

It revealed prison authorities have no idea how many of the inmates are taking drugs due to a failure to carry out mandatory testing.

And a number of serious assaults on staff and inmates mean some convicts are too frightened to come out of their cells.

Staff vacancies have been blamed for the problems, with the shortage affecting “every area” of the Sheppey prison.

Other areas of concern included prisoners spending too much time locked in cells.

The inspection carried out between April 28 and May 2 this year.

The report said the staff shortage meant the jail’s ability to identifying and manage risks was being undermined.

However, inspectors also said good relationships and communication between staff and inmates and a generally good environment lessened some of the effects of the shortages and most prisoners said they felt safe.

Healthcare was “reasonable” and the site was clean and in a good condition.

The availability of offender behaviour programmes met the needs of the population and was described as a real strength.

Nick Hardwick, chief inspector of prisons, said: “Some of our concerns about HMP Swaleside can, and should, be addressed by the prison itself.

“However, other much-needed improvements, which go to the heart of the prison’s challenges, require staffing levels to be brought up to at least the agreed levels and to do this the prison needs much more effective support from the centre.”

Michael Spurr, chief executive officer of the National Offender Management Service, said: “Since this inspection took place Swaleside has been receiving temporary staff support from other prisons to enable the Governor to provide a consistent, safe and purposeful regime for prisoners.

“We are actively recruiting permanent staff in prisons across the South East and Swaleside will continue to receive support until permanent staff are in place.

“Safety is a priority for the Governor - and action will be taken to address the recommendations made in this report.”

An Independent Monitoring Board report published last month into Swaleside said the quantity of weapons discovered was worrying but it has maintained a safe and decent environment for prisoners.

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