The Prime Minister is playing a tough hand as well as he can, but remains a weapon for Scottish separatists

The attempts to frighten the Scots with the ill-thought-through financial, economic and legal consequences of independence have been mildly counter-productive

The referendum campaign in Scotland is one of the most fraught and delicate operations in political history, on both sides. The stakes are high and the part played by emotion makes the outcome unusually unpredictable. It is a vote that neither side wanted. For Alex Salmond and the Scottish National Party, victory in the Scottish Parliament elections in 2011 came too early, running ahead of support for independence. For David Cameron, it was a vote he was forced to concede with all the appearance of good grace, because to have stood in the way of the SNP’s mandate would only have fed the beast of Scottish grievance.

And it is a campaign that the Prime Minister is required to fight with unnatural restraint, for fear of seeming to be a Home Counties Tory lording it over a country he neither cares for nor understands. Hence his modulated visit to Glasgow yesterday: no big speech, no rally, no crowds. Prefaced by a tactful article the day before in praise of John Smith, late leader of a rival party and regarded by many as the author of devolution.

So far, Mr Cameron has fought the campaign as well as it could be fought by an English prime minister whose party has virtually ceased to exist in Scotland. He must have been tempted to accuse Mr Salmond of cynically exploiting anti-Tory Scottish sentiment, and to have pointed out that the best rebuttal of the SNP bogey of permanent rule by the English was provided by the previous holder of his office, Gordon Brown. Instead, Mr Cameron’s speeches, when he has given them, have been thoughtful and measured. The more negative messages, about the flaws in Mr Salmond’s plan for a currency union with the rest of the UK, have been delivered by the Chancellor, the Treasury’s most senior civil servant and the Governor of the Bank of England.

Despite that, the attempts to frighten the Scots with the ill-thought-through financial, economic and legal consequences of independence have been mildly counter-productive. Yet so far, there has not been a single opinion poll - leaving aside one with a long pro-independence preamble to the question - that has found a majority intending to vote Yes to the question that will be on the ballot paper: “Should Scotland be an independent country?”

Two trends, which are probably linked, give hope to the nationalists. One is that the pro-independence side care more than the unionists. The other is Mr Salmond’s record of late surges. In 2011, the SNP took a weak and complacent Labour Party by surprise in the final weeks of the campaign. Those who want Scotland to remain part of the UK must hope that a vote for an SNP member of the Scottish Parliament is a very different matter from a vote for Scotland and the rest of the UK to be separate countries.

Mr Cameron is a prisoner of history. He became Prime Minister at a time when Mr Salmond was riding high, having conquered a lazy and entitled Labour Scottish establishment, only to find that the SNP leader would use Tory unpopularity in Scotland to power the final stage of his long, long campaign. Mr Cameron has played that hand about as well as it could have been played, but now it is time for others who support the union to match the strength of feeling of the separatists. We are better together and should be proud to say so.