Simon Hughes
Justice minister Simon Hughes has said half the women in jail should not be behind bars Getty

Justice Minister Simon Hughes is right to call for more widespread use of programmes for minor female offenders and to halve the number of women in prison.

Prison is a brutal punishment for all but women face disproportionate hardship; more are in prison for less serious offences; they are more likely to have been victims of abuse; mental health problems are more prevalent in female than male prisoners; and, of course, there is the issue of motherhood.

Speaking to BBC Radio 5 Live Breakfast, Hughes said female offenders are a "special case" and should be treated differently. "There are so many women who ought not to be in prison," he said. "About half ought not to be there at all. I met a woman in her twenties the other day who clearly ought to be sectioned. Her problem is a health problem, not a criminality one. Prisons shouldn't have to cope with that."

Hughes' announcement will likely send men's rights activists into a frenzy but the principle of equal treatment does not necessarily mean everyone should be treated the same. Where the underlying circumstances of female and male prisoners are different, different approaches are needed to achieve equitable outcomes. This is a basic tenet of equality law.

The women's prison population in England and Wales more than doubled between 1995 and 2010, and there are around 3,800 women currently incarcerated. Nearly half of all female offenders leaving prison are reconvicted within a year of release. Moves are desperately needed to tackle this vicious cycle of imprisonment and reoffending faced by many female inmates.

There are so many women who ought not to be in prison. About half ought not to be there at all
- Justice Minister Simon Hughes

The majority of women in prison pose no threat to society – 81% are jailed for non-violent offences. According to the Prison Reform Trust, eight out of 10 women entering prison under an immediate custodial sentence have committed non-violent offences – compared with seven in 10 men. Despite the number of female prisoners nearing 4,000, the small proportion of women means they are overlooked in national policymaking.

At the same time, the impact of a prison sentence is often greater on women than men. Compared with men, rates of mental illness are significantly higher among women in jail: 30% will have had a psychiatric admission before coming to prison, even more – 37% - have previously attempted suicide. A study published in the Lancet in December found a quarter of all female prisoners self-harm. Women only make up 5% of the prison population of the UK but account for 28% of self-harm cases.

Reasons range from historical sexual or physical abuse to distress at separation from their children. Last year, the Surveying Prisoner Crime Reduction study found six in 10 women in jail had dependent children, and a third of mothers are single parents before imprisonment.

For many female prisoners, the sentence does not end after leaving jail. Nearly a third of women lose their accommodation and, compared with men, are less likely to have good employment outcomes on release. A significant proportion of foreign national women in prison are known to have been coerced or trafficked into offending.

For those unconvinced by the moral arguments, imprisoning mothers has an undeniable knock-on economic effect, costing the state more than £17m over a 10-year period as a result of the increased likelihood their children will become Neets – not in education, employment of training. Non-custodial sentences would reduce this probability of poorer long-term prospects for children, leading to additional savings to the state.

Most of the solutions to women's offending lie outside prison walls, in treatment for addictions and mental health problems, protection from domestic violence and coercive relationships, secure housing, debt management, education, skills development and employment. Community sentences enable women to take control of their lives, care for their children and address the causes of their offending.