For two decades, this country has had liberal liquor regulations. These were introduced in the expectation that, over a period, they would prompt a mature drinking culture. Time, however, has exposed unforeseen flaws in that proposition.

The upshot is that Parliament will today begin debating the final stages of legislation designed to address excesses, including binge-drinking among the young, that are widely attributed to this liberalism. Most pertinently, a conscience vote will determine whether the minimum age at which somebody can legally buy liquor will be restored to 20, remain at 18 or, as a compromise, be split between 18 for drinking in licensed premises and 20 for buying from bottle stores, supermarkets and dairies.

Much of the opposition to a stricter approach is based on youth being penalised disproportionately for a problem that is the responsibility of all generations. Proponents of the current law also ask whether it would be fair to deprive people who are full citizens in all other respects the right to buy liquor in bulk until they are 20. Their argument, however, pays no heed to scientific evidence that has come to light since the law was liberalised. Most worryingly, this highlights the impact of even moderate levels of alcohol consumption on the still-developing adolescent brain.

The fruits of this work were brought together by the Prime Minister's chief science adviser, Sir Peter Gluckman, last year when he investigated the death from alcohol poisoning of a King's College pupil, James Webster. Sir Peter found that neuroscience now reckoned human brain development was not complete until people were well into their 20s. Most significantly, the last brain functions to mature were those that controlled impulses and judgment of risks.


This led Sir Peter to recommend that youth drinking problems should be addressed, particularly, by raising the drinking age to 21 and increasing liquor prices. The Alcohol Reform Bill does not go that far. Nor does it incorporate some of the suggestions of a 2009 Law Commission report, notably those making liquor more expensive and stifling advertising. But in seeking to curtail binge drinking and stop the proliferation of liquor outlets, it does include the split-age option, a key commission recommendation. Of the three alternatives on the liquor purchasing age, this is the most sensible.

The issues that have prompted the legislation relate largely to binge drinking and the on-supply of liquor to under-18s. This can be controlled in licensed premises. Problems arise mainly from alcohol sold in bulk from supermarkets and liquor outlets that is consumed in cars, at parks or in the home. There is logic in restricting those sales by raising the age to 20. Equally, however, 18 and 19-year-olds, who can vote and fight and die for this country, should not be denied the right to buy a drink in the supervised environment of a bar.

In the lead-up to the conscience vote, many MPs have been grappling with the options. Some have waited for responses from their constituents. Opinion polls suggest these will show an overwhelming desire to raise the age to 20. But conscience votes are never predictable, and it is conceivable that the sequence in which the options are voted on could be crucial, no matter how much care is taken to try to ensure none is disadvantaged.

The Prime Minister has indicated his backing for the split age. That compromise should carry the day. If the liberal approach has sparked unacceptable consequences, there is no need for a wholesale recourse to the tight controls of the past.