INMATES at Guys Marsh Prison are being punished with an increasing number of additional days’ imprisonment for incidents of rule-breaking – a rise of more than 107 per cent since 2015.

In 2016 prisoners were handed 6,823 extra days of additional punishment, compared to 3,296 in 2015, according to the new figures released by the Howard League of Penal Reform.

The charity claims that the increase in extended sentence reveals that “prisons are routinely and increasingly resorting to draconian punishments in a counter-productive attempt to regain control”.

Figures, released in the publication Out of Control: Punishment in Prison, show that at Winchester Prison the number of days added on totalled 1,540 – up more than 82 per cent on the previous – while Erlestoke Prison saw a decrease of 26 per cent to 2,140 days.

Across the South West prisoners were handed a total of were handed a total of 32,829 days – almost 90 years – of additional imprisonment for breaking rules last year.

Frances Crook, chief executive of the Howard League for Penal Reform, said: “Prisons are out of control. More people than ever before are losing their lives to suicide, and violence and self-injury are at record levels. The adjudications system has become a monster that is making these problems worse.

“It is surely time to follow the example set in Scotland, where scrapping additional days’ imprisonment has made prisons fairer and safer. There are more constructive ways to deal with misbehaviour than simply locking up people for longer, which puts even more pressure on the system.

“Bold but sensible action to reduce the prison population would save lives and prevent more people being swept into deeper currents of crime, violence and despair.”

The report calls on England and Wales to follow the example set by Scotland, where the use of additional days of imprisonment was scrapped about 10 years ago.

Officials and governors in Scotland could find no evidence that abolishing the use of additional days had a negative impact on behaviour, and Scottish prisons have become safer since the change was made.

Across England and Wales almost 290,000 additional days of imprisonment were handed to inmates during 2016 – a 75 per cent rise in only two years – which, according to the charity, cost the taxpayer about £27million.