It was certainly right for the Government, as a mark of respect to the Princess of Wales, to call a temporary halt to the Scottish referendum campaign. What is more it may make a difference: the referendum is only nine days away; and the last two weeks were always seen as crucial. Apathy, and a consequently low turnout, perhaps 50 per cent or even less, has always been what ministers feared most deeply. And so far a series of distractions, over which Donald Dewar, the Secretary of State for Scotland, has inevitably had little control, have made it much more difficult for the Yes campaigners to inspire real excitement among Scottish voters about how a parliament might improve their quality of life.

First, the light thrown on the putrid state of politics in Paisley sharply reminded everyone that the west of Scotland, at least, has rather more that its fair share of Labour politicians who should not be let loose on a parish council, let alone a parliament. Secondly, quite a lot of awkward questions, for example about the detailed operation of the Scottish parliament's tax powers have been asked - which either cannot be or have not been answered because it is a pre-legislative referendum. Thirdly, the broken-backed state of the Tories in Scotland has created the uncomfortable oddity that the greatest asset of the opposing No campaign has been Tam Dalyell, the one Labour backbencher with the courage or bloody-mindedness to challenge the proposals in public.

But there is something more deeply problematic about the campaign - something which quite a few London ministers in UK-wide departments have started to worry about in private. And that is the appearance of Scottish National Party politicians with Labour on joint platforms run by the "Scotland Forward" pro-devolution campaign. This uneasy alliance was bought at a price: Donald Dewar has not exactly gone out of his way to emphasise the argument, which used to be the devolutionists' stock-in-trade, that one of the central purposes of the measure was to preserve the Union. Instead, he has quite mildly said that while Scotland has always had the option of breaking away, it has never shown any desire to do so; and that if it has the power to call a referendum on independence it would be still be up to Westminster whether to grant it. This was enough for Salmond gleefully to claim last month as he stepped aboard the Yes campaign that the Government had now accepted that "the issue of independence will be determined by the people of Scotland".

Salmond's gloss is not, of course, what the White Paper, so masterfully unveiled in Parliament last month by Dewar, says at all: it makes it clear that because the British constitution will be an issue reserved to the UK parliament; independence is a matter, in the last resort, for Westminster and not Edinburgh. The source of anxiety is that because Labour and the SNP are supposed to be fighting the same campaign this canard cannot be nailed without the appearance of serious disarray. Indeed, when Jim Stevens, a Strathclyde University academic who sits on the Scottish Labour executive, said earlier this month that the the presence of the SNP was about as useful to the campaign as "an ashtray on a motorcycle", the speed with which the Scottish Labour hierarchy distanced itself from his remarks was wonderful to behold.

The reasons for Labour to worry about this are two-fold. Tactics first. There is a danger that some unionist Scots may be deterred from voting "Yes" let alone "Yes, Yes" when they are assured by Alex Salmond, not to mention Sean Connery, that the parliament is a stepping stone to independence. After all Salmond is an astute politician. If he says that a Scottish parliament is likely to hasten independence and only the barmier elements of the SNP say it is a sell-out and a government trick to shore up the Union, sensible electors may be more inclined to believe Salmond.

That was not, however, the calculation made by the Scottish Office. On the contrary, ministers decided that to be certain not only of a good majority but a good turnout as well, active steps had to be taken to ensure the presence of leading nationalists in a joint campaign. They were unpersuaded by the counter-argument that SNP supporters would have backed the parliament anyway. And they were prepared to take the risk that it might switch some voters off the idea of a Scottish parliament. They therefore rejected the alternative strategy: to confine their own campaign to the parties - Liberal Democrats and Labour - that made up the cross-party Scottish Constitutional Convention and leave the SNP (which walked out if it) to do its own thing.

Whether the Government was right about this should be reasonably easy to see once the votes are counted and analysed after Thursday week. Much less tangible is the effect, if any, on the long-term prospects for an independent Scotland. Maybe the pulling of Labour punches against the SNP will not make the slightest difference one way or the other. But whether it does or not, there has been something intellectually slightly disreputable about the cross-party campaign. Dalyell is incontestably right about the central problem of the temporary marriage of convenience between Labour and the SNP: they cannot both be right. It cannot be true both that the Scottish parliament is the way to preserve the Union and hasten Scottish independence. And the danger of glossing over that difference is that the electors are being told, in effect: "Vote Yes, we don't mind why." And that is a confusing, not to mention less than inspiring, message.

To many Scottish politicians this will sound like a cavil too far. The Government was right to reject calls from Dalyell yesterday for postponement of the referendum itself. To do so would require the recall of the Commons and the answers Dalyell wants are not going to come, however the long the delay. But if the Government's campaign is finally to take off in its - rightly - truncated final stages then it needs to demonstrate more fully that a new tax-raising parliament will bring tangible benefits to Scottish citizens. It needs to remember that the parliament has never meant as much to the public at large as it has to politicians - not to mention that the victory of 1 May removed one of the deepest grievances among the Scottish people - that they kept voting Labour and kept getting Tory governments. The impact of the brief truce is uncertain: it should be used to find ways of genuinely exciting interest in the new parliament; and not merely as an excuse for the low turnout that is the Government's worst fear.