OKAY, someone has to say it.

If Cornton Vale prison for women offenders is going to be torn down, as advised by the widely-praised Angiolini Report, how can all the others remain open? If it is wrong to lock up women for relatively trivial offences, aren't we going to have to apply the same reasoning to male offenders?

The argument in the report is that most women prisoners have mental health problems, chaotic lifestyles, low self-esteem and a history of addiction. But doesn't that apply to the vast majority of all prisoners? According to the Scottish Association for Mental Health, 90% of male prisoners have mental health problems too. There's a lot more of them too, since women are only 6% of the prison population.

True, the number of women prisoners has doubled in a decade and it makes little sense for most of them to be there. But this is because imprisoning people has become a national obsession. Britain locks up more prisoners than any country in Europe. Scottish jails are bursting at the seams, even as crime falls, largely because voters are so keen on putting people in jail. Dame Elish should realise this better than most since, as Lord Advocate, she sat in the very Labour-led Scottish cabinets of the last decade that put pressure on the courts to hand out more custodial sentences to men and women.

Her Commission on Women Offenders rightly condemns the waste of money in locking women up in what become, essentially, colleges of crime and abuse. Ms Angiolini says that the vast majority of women prisoners end up re-offending, and she's right: two-thirds of all prisoners reoffend within two years. She says that family life suffers as a result and that women offenders should be given counselling and non-custodial sentences that keep them in the community. Absolutely, but I can see no reason why this should not apply equally to male offenders, most of whom are also inside for short sentences.

The tragedy is the number of young men in prison on remand or for non-payment of fines who become ensnared in a criminal subculture from which they never escape. This really has very little to do with gender and a lot to do with the psychology of incarceration. Which is why I'm troubled by some of the implications of the Angiolini Report. Can you say prison is the right punishment for men but the wrong one for women? Does that not write gender inequality into the very criminal justice system? Can you really apply one law for men and another for women?

There is an unspoken assumption that criminal behaviour is more excusable among women because they have been oppressed by men and, being carers, are not inherently bad persons. It is argued that the prison experience is worse for females. "For many women in Cornton Vale there's a complete lack of hope for the future," said the former Lord Advocate yesterday. "They've lost their children, they've lost their council house because they've been in prison for more than a month, they're isolated and their problems are not tackled." Again, I can't see that the prison experience is much less damaging for men, the vast majority of whom lose hope, lose their homes and families and end up re-offending or becoming alcoholic.

Cornton Vale is a particularly grim institution – overcrowded, high suicide rate, poor facilities, lack of rehabilitation. It would be none the worse of bulldozing. But Barlinnie prison isn't exactly a holiday camp either, and suicide, like hard drugs, is a part of everyday prison life. Elish Angiolini says that "we have a penal system in Scotland designed for men and largely based on a Victorian notion of punishment". I'd have to agree that our penal system is based on essentially Victorian values. But we have to be careful not to reinvent the most Victorian myth of all: that women could not by their nature commit crime and therefore didn't need prisons.

I'm afraid women can be just as badly behaved as men, as the doubling of female prisoners suggests. There's been a significant increase in violent behaviour by women, as Dame Elish herself noted in evidence to the Holyrood Equalities Committee in 2008. We live in a culture saturated by alcohol, violence and drug abuse, and it doesn't make sense to suggest that crime is just a male thing, just as it is a myth that only women suffer from domestic violence. Perhaps one of the unintended consequences of gender equality over the last 20 years is that women are now being treated more equally by the courts, which is why more have been finding themselves in Cornton Vale.

Granted, it does seem ludicrous to imprison women for not paying their television licences, but it is senseless sending anyone to jail for non-payment of trivial fines. So why do we do it? Well, here's one reason. The Scottish Justice Secretary, Kenny MacAskill, was savaged by Labour for calling for offenders inside for six months or less to be given community sentences. Labour's leader, Johan Lamont, called this "the SNP's get out of jail free card for criminals". Indeed, Labour's argument at the last election was, far from closing down prisons, that there aren't enough of them being built. The public must be protected, they say. Prison works. If you can't do the time, don't do the crime. This is the kind of populist argument that goes down well during election campaigns and all parties are guilty of it to some degree.

The politicians will have to do some rethinking on this issue because the Angiolini report has fatally undermined the custodial approach to criminal justice. The conclusion is inescapable: the use of imprisonment should be restricted to those who have committed serious offences or are a danger to the public – irrespective of sex. As the McLeish Report said four years ago, you could cut the prison population by 3000 tomorrow if you applied a bit of common sense to sentencing. Elish Angiolini may not yet realise it, but in passing a death sentence on Cornton Vale she has condemned the rest of the penal system too. The truth is that prison doesn't work – for women or for men.