Schemes of Scottish home rule go back to just after Gladstone's introduction of his Irish Home Rule Bill. Indeed, they were then part of what was called "home rule all round", leaving the Westminster parliament to deal with imperial matters. At various times, Scottish Home Rule Bills have almost got through parliament. One did in 1978, but was rejected by referendum in March 1979, under the requirement that 40 per cent of the electorate should vote in favour.

This history suggests that, while the demand has been constant, or at least recurrent, it has not been very deep or held very strongly. If that had been the case, it is inconceivable that home rule would not have been achieved by now.

This points to the significant difference between Scottish and Irish history. Scotland was never conquered or colonised. It entered into a Union with England by a vote of its own parliament. Scots saw themselves as equal partners in the British empire. In the 19th century, Scots were not a submerged people, like the Irish, Poles or Czechs. On the contrary, they felt themselves to be a dominant one.

That feeling faded in the 20th century. Early industrialisation made Victorian Scotland self-confident and dynamic. While confidence faded as the old, heavy industries ran into trouble between the world wars, the nationalism that then sprang up was shallow-rooted, romantic and backward-looking.

The response to industrial decline was to cling even more to the British state, which had the resources to palliate its effects, and ease a transformation to a new economy - or, indeed, as many hoped, to prop up the declining industries.

Moreover, the experience of the second World War reinforced a sense of British patriotism. It was Britain, not England or Scotland, which stood contra mundum. Significantly, the great air battles of 1941, though mostly fought over southern England, were unanimously called the "Battle of Britain".

For 20 years after the war, Britishness reigned almost unchallenged, despite the apparent success of the Covenant Movement of the

1940s, which called for a vague measure of home rule. The Labour Party was committed to socialism in one country and forgot its historic, if nominal, attachment to home rule.

It was not until the Wilson years of the 1960s that the decline of British power, and the apparent failure of British governments to check Scotland's economic decline relative to more fortunate parts of the UK, gave a new impetus to nationalism.

It was the rise of the Scottish National Party in the feverish atmosphere of the 1970s which persuaded Labour to introduce a scheme for devolution.

From the first, this was bedeviled by its internal contradiction. Devolution appealed to nationalist sentiment but its ostensible purpose was to strengthen the Union by making for the better government of Scotland within the framework of the UK.

Devolution could, therefore, only work only if it stifled the nationalist feeling which it also fed, and on account of which Labour had been brought back to its home rule roots.

The condition of devolution was that there should be a strong SNP seeking independence; the condition of the successful working of any scheme for devolution was that the SNP should find its support wither away.

Undoubtedly, the unpopularity of the Thatcher-Major government in Scotland made devolution more attractive. Though general policy was made by Scots and administered by Scots, there was, nevertheless, talk of "a democratic deficit".

There were demands that the very real and considerable administrative devolution which had taken place should be matched by political devolution in the shape of a Scottish parliament.

After 1987, Labour was committed to this, partly because of the natural frustration resulting from its inability to translate electoral support in Scotland into political power, and partly for fear that, in the absence of devolution, its support would seep away to the SNP.

So we find ourselves poised now to vote for a Scottish parliament on the lines proposed in the British government's White Paper.

Its areas of competence will be those parts of government already administratively devolved to the Scottish Office. If we approve, it will also have a modest tax-raising power and, on account of its control of local government, the power to change local government taxation.

The modesty of the scheme might, one would think, commend it. Yet, though the result is likely to be a handsome majority in favour, there are still unionists who view the scheme with suspicion and dismay.

They do so for four reasons. The first is simple. While the government presents its proposals as, in the words of the Secretary of State, Mr Donald Dewar, "a fair and just settlement for Scotland within the framework of the United Kingdom", Labour has welcomed the support of the nationalists who see what is proposed not as a "settlement" but as a stage in the process towards independence.

It is clear that both can't be right. Therefore, many who are happy to identify themselves as both Scottish and British are inevitably devosceptic.

Second, the tax-varying powers, though modest, worry many businessmen. They fear that if Scotland becomes the most highly-taxed part of the UK, as seems probable, they will be put at a competitive disadvantage. Their doubts are echoed by those who think the whole thing an expensive extravagance which will only benefit professional politicians and create more jobs for the boys.

Third, some of us fear that one consequence will be the diminution of Scottish influence, now considerable, within the UK. A semi-detached country is unlikely to play a full part in the government of the whole. Scotland may become more inward-looking and parochial, as Northern Ireland was in the days of Stormont.

The refusal of the government to attempt any answer to the West Lothian Question, framed 20 years ago by the now veteran Labour MP for Linlithgow, Mr Tam Dalyell (then MP for West Lothian), which asks why Scottish MPs at Westminster should be able to vote on a range of English affairs but English MPs should not on comparable Scottish affairs, is worrying. Ultimately, the only answer to this problem would be some form of federalism.

Finally, the proposed scheme will create a parliament that is fundamentally irresponsible because, despite the modest tax-varying power, it will depend for its revenue on Westminster. It will have the pleasure of spending money while it has not incurred the odium extracting it from the people.

Writing recently on the problems of local government in the west of Scotland, Iain McWhiter (who favours devolution) suggested that it was important to "restore the local tax base".

Part of the problem, he said, was that local councils no longer raised the money they spend. "Nothing could be better designed to undermine civic responsibility. The balance should be restored, with more tax raised locally and less raised centrally. Councils would then be answerable to their local electorate."

He is quite right and yet we are being offered a so-called national parliament which will raise a still smaller proportion of its revenue that the meanest and poorest local authority now does. Nothing, in his words, could be better designed to undermine civic responsibility.

And that, even if one did not see the proposals as institutionalising friction between London and Edinburgh, to the likely benefit of the SNP, would be a sufficient reason to vote "no" on September 11th.

Allan Massie is a journalist and novelist who lives on the Scottish borders. He writes regularly for several publications, including the Scotsman and the Daily Telegraph. His most recent novel, published last month, is Shadows of Empire.