The Alcohol etc (Scotland) Bill is out today, and the political big guns have been firing salvoes over whether setting a minimum unit price for alcohol is (a) illegal, (b) unfair, and (c) a daft idea anyway.

With Labour having finally declared itself alongside the Conservatives and Liberal Democrats as against the idea, it looks at present as if we will not be given the chance to see it tested, in court if need be, who is right on the competition law issue – i.e. whether it is possible to justify such a measure on health grounds even if it has an impact on the workng of the free market.

To my mind this would be rather a pity, and not just from the legal interest in learning how the question would be authoritatively answered. There is surely a public interest in knowing where the boundary lies between such powerful opposing considerations, for the benefit of future policymakers across the continent as well as in this country.

I cannot help feeling that there are politicians in more than one party who are not being entirely open about their motives in the way they have approached the issue. We managed a cross-party consensus on the smoking ban, and it is commonly believed to be the point at which many of the public realised that the Scottish Parliament could indeed have a direct impact on their lives.

But with alcohol there are important Scottish industries and jobs at stake, and a powerful commercial lobby fighting its corner, and the political pressures on MSPs, individually and collectively, are many and subtle. As a result, while all can agree that too much alcohol is being drunk by too many people, agreeing what should be done about it is a lot more difficult.

The minimum price proposal has been criticised on other grounds, such as resulting in more revenues for big supermarkets, not affecting some drinks such as Buckfast, and more. How far such points are valid, and whether they could be effectively tackled – and likewise the potential legal obstacle – I don't know. But I do have a regret that the currently entrenched antagonisms at Holyrood have prevented a more collaborative approach, given the weight of opinion of health professionals (and others) that yes, we could make a real difference this way.