Scotland is lucky to have, in Andy Wightman, a dogged campaigner on the vexed issue of land reform.

This is the subject of a documentary on BBC tomorrow night and I hope and expect that it will ventilate many aspects of an issue which is highly emotive, but has prompted comparatively little political action for generations.

Andy Wightman has for a long time been raising questions such as: what happened to all the supposedly "common land" in Scotland? Can we get it back? Why and how do so few people own so much of our land? Can the people ever recover some of these huge expanses of real estate?

In his quest for land justice he has been a critic of, among others, the royal family, the Scottish legal profession, and many, though not all, of Scotland's major private landowners.

I've heard him lecture, and have read his books. He is no chippy class warrior, but rather an independent, open-minded and doughty activist who does his research very thoroughly before moving on to the campaigning.

I never really reflected on the land issue, which is an authentic public scandal, till I learned how land, rather than the actual property on it, is excessively expensive.

I became aware of this when a couple I knew bought a house in rural central Scotland that had a plot of land beside it.

They understood that this small plot would rapidly accrue in value. It did, and it was duly sold, with planning permission for a house to be built on it, about a decade later.

What intrigued me was that it was the land, rather than the actual cost of the new house, which was expensive.

I should have realised this was the case, because a leading Scottish housebuilder once told me, not in any arrogant way, that his business was not really about building or selling houses.

It was all about acquiring land (and, by implication, building up land banks). The land on which it is built can often represent more than the "worth" of half a house.

That is one of the problems, perhaps the main one, concerning land ownership. But of course there are many others, as Andy Wightman has exposed. A positive recent development has been the growth of democratic land ownership, through purchases by community organisations and, to a lesser extent, conservation bodies.

Such initiatives are welcome, but they tend to take place in rural areas, and in the north and west rather than the south and east of our country.

As Andy Wightman has said, community ownership ought to be more common in our cities, instead of being largely confined to rural Scotland.

But, of course, it is the vast tracts of non-urban Scotland where the disparities of ownership are most acute and emotive.

Paul Wheelhouse, the Scottish Environment Minister, features in the documentary, in which he says he would "not have designed" a system where so few people own such a huge amount of land (and, by extension, wealth). Fewer than 450 individuals possess more than half the land in our country.

The minister's language is diplomatic. Perhaps Mr Wheelhouse wants to avoid pre-empting the conclusions of the Scottish Government's coming, and hopefully radical, report on land reform.

One of the problems that will face politicians who do try to do something about this wide ranging scandal is that the vested interests are very powerful; they can employ articulate spokesmen and expensive lawyers.

There are not that many people actually living on their estates; and those who do may, understandably, be reluctant to say much about the situation publicly.

Meanwhile I am not an expert on forestry, agriculture, tourism or wildlife - far from it - but Andy Wightman is, and I know that he is not convinced that such industries and interests are best served by the present system, to put it mildly.

Here is a scandal that an independent Scotland would have to address urgently.

Meanwhile it looks as if the Scottish Government is, belatedly, paving the way.