A week is a long time in politics. Last Friday I wrote a post for this blog which said David Cameron was warming to the idea of minimum unit pricing for alcohol. By Monday, reports were circulating that he had defied opponents in his Cabinet and announced his intention to press ahead with the idea. Now we hear that the Scottish Conservative Party have dropped their objections to minimum pricing, and are prepared to support the SNP in bringing it onto the statute books north of the border.
That it is the Tories, rather than Labour, who have been first to throw their weight behind minimum pricing is remarkable enough: it is, after all, a concept entirely at odds with free market principles. Equally remarkable, however, is the sheer speed with which the idea of minimum unit pricing has moved from the margins to the centre of alcohol policy debates.
Five years ago, almost no-one in Britain knew what 'minimum unit pricing' meant. The idea appeared in a report published by Scottish Health Action on Alcohol Problems in 2007, but the turning point was the decision by the Department of Health to commission researchers at the University of Sheffield to model options for tackling cheap alcohol in 2008.
When published, their report provided enormous impetus to the new idea of minimum pricing. The following year it was adopted by the Chief Medical Officer and, in 2010, supported by the Health Select Committee in their report on alcohol. The Sheffield report also provided a substantial research base for SNP policy on the issue.
The adoption of minimum unit pricing by the SNP was a seminal victory for supporters of 'public health' approaches to alcohol policy. For decades, they had been arguing that alcohol was 'no ordinary commodity' and the State had a duty to reduce overall consumption through, among other things, price regulation. However, until very recently the means they proposed to achieve this was conventional taxation.
But politicians have long feared the electoral fallout from imposing a blanket tax on alcohol. It smacks too much of indiscriminate revenue-grabbing; of that spectre which haunts social policymakers of all stripes - the accusation they are imposing a 'nanny state'.
The key innovation of minimum pricing is that it sidesteps this by impacting only on the cheapest drinks: white cider, cheap spirits and so forth. And it is here, somewhere among the Scrumpy Jack and the discount vodka, where, in the arena of public opinion, the defence of individual liberty starts to lose ground to the fear of Binge Britain.
In 2009, David Cameron rejected minimum unit pricing on the same grounds politicians had always rejected blanket tax increases: that it punished the majority of moderate drinkers for the excesses of the minority. Now, it seems, he and his colleagues in the Scottish Conservatives have calculated that enough people are concerned about very cheap alcohol to outweigh the pushback from those who feel their pockets are being pinched.
Existing evidence seems to support that view: putting minim unit pricing in their manifesto didn't, after all, harm the SNP at the last Election.
Whether minimum pricing will make a difference to overall consumption remains to be seen, and Scottish Conservative support for the policy is dependent on a five-year 'sunset clause' - which will raise all sorts of questions about the criteria by which the success of minimum pricing is to be judged.
Figures released yesterday show alcohol consumption in England and Wales continues to decline overall (as it has for some years now), so it may prove hard to make the link with minimum pricing were it to be introduced and the decline to continue. On the other hand, evidence may show - as the Sheffield model suggests - that is has a particular impact on harmful drinkers, whose consumption causes most problems for the NHS, and young binge drinkers.
Perhaps, though, minimum pricing is most significant for its political symbolism: because it amounts to a political acceptance of the principle that alcohol is, indeed, 'no ordinary commodity'. Its adoption in Scotland would, therefore, signal a considerable victory for public health campaigners, not least because it would set a powerful precedent for other countries to follow should they wish. If England were to be one of those countries a domino effect could be set in motion.
If Cameron gets his way, the impact of minimum pricing on consumption could take years to ascertain; its impact on the political status of alcohol, though, would be immediate.