Tens of thousands of extra days behind bars handed out to punish serving prisoners are contributing to jails becoming "out of control", campaigners have claimed.

Lobbyists have spoken out after statistics were released showing nearly 4,000 extra days were enforced for lags serving time at HMP Dovegate, just outside Marchington.

The revelation comes after a damning report by Prison Service inspectors found high levels of drug use and violence in the Moreton Lane facility.

But bosses at the Category B prison, run by private firm Serco, handed down far fewer extra days than many jails in the UK.

New figures show a staggering 42,756 days were added to sentences in prisons across the West Midlands in 2016. This is the equivalent of 117 years.

Now the Howard League for Penal Reform and Prison Officers' Association have called for a review of how prisoners are punished for bad behaviour.

Adding additional days as a punishment was scrapped in Scotland 10 years ago and campaigners are calling for policy-makers in England to follow suit.

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."

Across England and Wales, nearly 290,000 extra days were enforced last year - a 75 per cent rise in just two years.

The Howard League, which published the findings in its report - Out of Control: Punishment in Prison - has calculated those days will cost the tax payer around £27 million.

Although 3,968 extra days were enforced at Dovegate, which had 1,109 prisoners last year, other jails have generally handed down more.

A total of 12,100 were imposed on prisoners in Aylesbury prison last year – more than any other jail in England and Wales.

During the same period, Bedford – a similarly-sized prison located only 26 miles away – saw only 411 additional days’ imprisonment handed down.

A Prison Officers' Association (POA) spokesman said: "POA support the claims from the Howard League that prisons are out of control, awash with drugs and dangerous places to live and work.

"Additional days are not a draconian punishment, but a means to ensure prisoners are aware that there are consequences to their unlawful behaviour whilst in prison.

"The POA has asked for all assaults to be prosecuted through the courts unfortunately all too often the police and CPS refuse to prosecute as it is not in the public interest. This may be a contributory factor in this massive increase identified by the Howard League.

"Prisons have been brought to breaking point by overcrowding, loss of cellular accommodation following riots, serious disturbances and staff shortages.

"The Howard League has calculated that the additional days imposed in 2016 alone will cost the taxpayer about £27million.

"However, the POA claim that the hidden costs due to the acts of violence, drug use and disturbances will far outweigh these costs to the tax-payer.

"The POA support the view of the Howard League in that the adjudication system lacks consistency as governors often hand down alternatives to additional days or use the local judge to deal with acts of violence.

"This often leads to a more lenient punishment than if the case was heard and prosecuted through the courts.

"Prison is an occupational hazard for many offenders and additional days are a deterrent in some cases but mean nothing to others."

A Prison Service spokesman said: "The prison discipline system upholds justice in prisons, ensures actions have consequences and empowers governors to make the right judgements for their circumstances and their prisons.

"The vast majority of offenders leave prison without serving a single additional day.

"But the public and our hardworking staff rightly expect that those prisoners who choose to break the rules, making life more difficult for staff and other offenders or putting their safety at risk, should face the consequences."