The wowsers are back on a futile mission to enforce public morality through statute.

In Australia, as in New Zealand, a new temperance movement is testing the boundaries of prohibition to encourage better manners. It advocates restricting the sale of alcohol and increasing the price to control excess consumption.

As with earlier temperance movements, however, a laudable social objective is muddled by a moral crusade. The early twentieth-century temperance movement attempted to impose their version of morality by preaching sobriety; today’s moral enforcers want to set the boundaries of appropriate behaviour.

Their justification is an apparent increase in public drunkenness in cities and towns, particularly among the young, and reported incidents of alcohol-fuelled violence.

In Australia, the federal government joined the crusade in 2008 by raising tax on so-called alcopops: sweet, pre-mixed spirits said to be a favoured tipple of the young. It was well received by the moral establishment, but had no practical benefit. Drinkers reacted to the price signal by changing their consumption patterns.

The wowsers’ untested assumption is that a late night culture of pre-loading and binge drinking is an indication of loser public morals and the corruption of youth. An alternative explanation is that public drunkenness is a consequence of loser policing and the corruption of public policy.

The offence of being drunk and disorderly was abolished in New Zealand, New South Wales, and most other Australian states some 30 years ago.

When a New Zealand Law Commission report recommended reintroducing the offence three years ago, the main objections were that it would impose an unreasonable burden on the police and unreasonably target Maori and other minorities.

Paradoxically, no such objections are raised to roadside random breath testing, a draconian and intrusive form of policing that, nonetheless, has a demonstrable public benefit.

There is unlikely to be a demonstrable benefit from the proposed ban on off-licence sales in Wellington after 9pm.

It will, however, produce a warm inner glow in those who advocate the measure. Like the temperance crusaders of the early twentieth century, the twin motives of doing good and being seen to do good have become intertwined.

We should resist the commandeering of the law as a platform for expressing private virtue rather than a means of enforcing public good.

Instead, if we are prepared to curtail public liberties to prevent drunks taking charge of a motor vehicle, why not consider similar measures to prevent them taking charge of a fist?