“First of all we’ve seen an increase in sentence lengths overall in the past couple of decades which has contributed to the near doubling of the prison population in that time. This is combined with a growth in the number of people serving indeterminate sentences – so that’s life [sentences] and also the IPP sentence, which has been abolished, but there still are significant numbers of people in prison serving that sentence.”

The IPP sentence, (known as the indeterminate sentence for public protection) was introduced as part of the Criminal Justice Act of 2003 and involves a judge setting a minimum time in prison for people, with the release to be determined by the parole board. So many prisoners end up staying in prison for extended periods, without knowing when their release date will be.

Mr Day from the Prison Reform Trust says when the IPP sentences were introduced, it was only meant for about 900 people; however the number of people who have received this sentenced is now 6,000, out of the total prison population in England and Wales of approximately 84,500.

He says that this is resulting in “thousands of people in prison, serving an indeterminate sentence for public protection.”

There are concerns being raised about the welfare of older prisoners, who represent a significant proportion of the constant prison population, with fears current prison facilities are not set up to cater for the demands of older people and those in need of care.

According to research, Mark Day from the Prison Reform Trust says that two out of five people over the age of 50 in prison have a disability.

“What it means with an ageing prison population is that you have a higher proportion of people in prison who have disabilities and social care needs. Also, prison staff aren’t trained necessarily to be able to deal with this change. When we’ve got a prison service that is coping with very significant cuts – we’ve seen a 28 percent reduction in the numbers of staff in public prison since 2010 – this is putting an additional service on the prison service at a time of very rapid change.”

He believes the lack of awareness and lack of structures in place to deal with older prisoners is having an adverse impact on their wellbeing.

“Essentially it means that people are being doubly punished. If they have a disability, they’re not only in prison because they’ve committed a crime – and obviously lawfully they are deprived of those rights - but they’re also being punished because of their disability, because they’re not able to take part in their prison regime. It also has health consequences as well because if the prison isn’t able to deal with people’s social care, it can mean that conditions can develop and become more serious.”

Despite the difficulty of caring for older prisoners, some positive developments are being made as part of the Care Act of 2014, which introduced provisions for local authorities to cooperate with prison services to ensure the social needs of those in prison are met.

“So that would involve an assessment of people as to whether they would be entitled to receive care from the local authority. If they didn’t meet the criteria, then the prison would have to pick that up. At least what it does do if provide a framework so that social care can be delivered in prison,” Mr Day said.

However despite these positive signs, he said more needs to be done to ensure the care of those older and disabled prisoners within Britain.

“What our research has suggested is that this provision is too patchy at the moment; it depends on the goodwill of individuals to ensure that social care needs of people are met. What we really need is proper national policy to ensure that the prison service is equipped and able to care for an ageing prison population.”