It is a really disturbing fact that 1 in 4 members of the prison population has a severe mental illness. Addressing this is one of the big social reforms which has not yet happened.

Far too often these conditions are diagnosed for the first time in prison. In many cases, their mental illness will have been a significant factor contributing to their criminal behaviour. If these people had been properly diagnosed when they first came into contact with police, and they had been provided with appropriate support and therapy, their offending actions might have been averted.

Identifying offenders with mental illnesses early on not only gives them a chance to rebuild their lives with the support they need, but can also prevent crime, and protect their potential victims. In too many cases of criminal offending, both the perpetrator and the victim of a crime have been failed by society – and rectifying this is important part of the Liberal Democrat goal of delivering a fairer society.

And so, I am delighted that we have announced £25m of funding to enable 10 police forces – covering about 25% of the country – to trial a new approach to managing offenders with mental illness. The 10 forces will be using a new model of “Liaison and Diversion” in police and court services. When people come into contact with the police or judicial system who have a mental illness, an assessment of their health needs will be carried out, making sure that information is shared between the police and court system and mental health services. This can then be used in making decisions about charging and sentencing, as well as to make sure that appropriate support is provided as quickly as possible.

Liaison and Diversion services are already making a significant difference in areas where they are used. On Merseyside, a 78 year old man who behaved in a threatening way despite previously having no record of offending was quickly diagnosed with dementia and, instead of being charged and potentially imprisoned, a support package was arranged for him in a nursing home by local health and care services, and he has not offended again.

As these trials progress, I will be monitoring them closely. Our aim is to extend the areas covered to about 50% of the country in 2015/16 with the objective of having nationwide coverage by 2017 if the case stacks up. At a time when we need to do more with finite resources, ensuring that vulnerable people get the support they need, and reducing preventable criminal behaviour, is essential to delivering a fairer – and safer – society. I am really pleased that Liberal Democrats in Government are helping to deliver a really important reform.

* Norman Lamb is MP for North Norfolk and was Liberal Democrat Minister of State at the Department of Health until May 2015. He now chairs the Science and Technology Select Committee