A quarter of prisoners at HMP Belmarsh are spending 22 hours a day locked in their cells.

According to a new report by the Independent Monitoring Board, staffing levels at the prison are good, but there is relcutance to ease the strict security regime in place there.

At a recent inspection the IMB found the regime was preventing prisoners from engaging ‘in any sort of purposeful activity’.

The chair of the IMB, a statutory body that monitors the welfare of prisoners in the UK, said: ‘Belmarsh can be a very challenging place and although staff are to be commended for the way they maintain day-to-day safety and security, this has resulted in limited opportunities for prisoners to engage in purposeful activity, education, or resettlement work.’

The body’s latest annual report on the prison also found other instances of prisoners being treated poorly in the jail.

Inspectors found that prisoners suffering from mental health issues are waiting far too long to access and be provided with appropriate living conditions to accommodate their needs.

Chair Peter Ward added ‘prisoners with severe mental health issues are not being moved to more therapeutic environments which also places a strain on prison staff and facilities’. Despite the contract for healthcare being awarded in February this year, at the end of the reporting year this June, the provision of mental health nurses had been reduced to less than one full time equivalent post.

Prisoners themselves have complained to the board about missing property, especially when transferring between prisons.

At Belmarsh, there are a small number of prisoners serving indefinite imprisonment for Public Protection sentences (IPP). They were given short tariffs over a decade ago.  The IMB considers keeping these individuals in prison for so long to be inhumane.