The UK has the highest number of prisoners serving life sentences in Europe, according to a report.

Analysis of 2016 data found UK jails were holding 8,554 inmates serving life – more than France, Germany and Italy combined.

Between them, Turkey and the UK accounted for two-thirds of the life-sentenced prison population in Europe, the study added.

The findings, based on analysis of Council of Europe data, are detailed in a report published by the Prison Reform Trust.

The PRT’s latest Bromley Briefings Prison Factfile includes a section on indeterminate sentences, by Professor Dirk van Zyl Smit and Dr Catherine Appleton from the University of Nottingham.

It said: “The UK’s use of indeterminate sentences is plainly out of kilter with the majority of international comparators.”

Peter Dawson, director of the PRT, said: “A substantial minority of the prison population is serving sentences characterised by an absence of hope and in many cases a sense that punishment, though deserved, has ceased to be proportionate or just in its administration.

“This has profound implications for the way of life prisons provide, if the treatment of those serving the longest sentences is to be both humane and purposeful.”

In its own assessment of the state of prisons, the trust said safety has deteriorated “rapidly” in the last six years, with more self-harm and assaults “than ever before”.

A Ministry of Justice spokesman said: “Indefinite sentences are reserved for society’s most dangerous criminals – those who commit serious sexual or violent offences like rape and murder and are a high risk to public safety.

“When indeterminate prisoners have served their tariff they can apply to the independent Parole Board who will consider whether they still represent a threat to society.”