David Cameron visits Wormwood Scrubs prison in 2012
On Monday the prime minister announced plans for six "reform prisons" in England and Wales as part of efforts to tackle violence and re-offending rates.
Pointing out that the cycle of re-offending costs the taxpayer up to £13bn a year, David Cameron said in a speech that the UK needs to show we are a "compassionate country":
The failure of our system today is scandalous... levels of prison violence, drug-taking and self-harm should shame us all.
I also strongly believe that we must offer chances to change; that for those trying hard to turn themselves around, we should offer hope; that in a compassionate country, we should help those who've made mistakes to find their way back onto the right path.
On average, the UK's prison system sees 600 self-harm incidents, one suicide and 350 assaults per week.
In a similar vein to the Conservative academy schools, prison governors will be granted autonomy over their operation and budgets, and there is to be a 'Teach First' style graduates programme to attract quality teachers to prisons.
The PM also promised to protect the current £130m prison education budget.
But while Cameron is the first prime minister in decades to take such an interest in prison reform, critics have pointed out that system standards have greatly deteriorated under coalition and Conservative government cuts since 2010.
Penal reform campaigners and charities are also worried that decentralising the penal system will open up prisons to even more privatisation - which has led to concerns over neglect of inmates as staff are slashed in favour of profits.
Campaigners have said that reforms won't work if inmates are "crammed into filthy institutions with no staff".
The six prisons will be created on existing sites, and the PM is expected to push for legalisation so the plans can be adopted more widely.