So you want your independence.

What will you do for an army? What makes you think the EU will have you? Where's your tax system? How, for that matter, will you cope when all those major employers and investors take fright at separatism and flee – don't say you haven't been warned – across the Border? What on earth makes you imagine a small economy can survive in the big, dangerous modern world?

A final question, for our files: do you feel Catalan, Spanish, or a contented bit of both?

Many things separate Scotland from Catalonia. We don't have the weather, for one obvious thing. Nor, with due respect to Celtic, do we have a football club to rival Barcelona. But there are striking parallels between the questions being asked of Catalan voters ahead of tomorrow's regional elections and the inquiries made of Scots.

Time and again, in fact, the questions are exactly the same, even when the answers are as different as the context. It is as though – but perish the thought – London and Madrid have put ministerial heads together in an attempt to contend with the force they insist on calling "separatism".

Of two prime ministers, nevertheless, David Cameron counts, just for once, as the smarter. Before the end of September the demand for independence had been quiescent in Catalonia. The principal ambition had been for greater autonomy from Madrid, fiscal autonomy above all. Confronted with the proposition, the government of Mariano Rajoy refused point blank to negotiate. So much for Hispano devo max.

Given that at least one million patriotic Catalans had already taken to the streets on September 11, their national day, this was not clever. The demonstration had emboldened Artur Mas, leader of the governing Convergencia i Unio (CiU) two-party nationalist alliance, to call for an independence referendum. Mr Rajoy responded by saying such a thing is forbidden by Spain's constitution. What's more, he had no intention of amending the document.

Hence tomorrow's early elections. Whether Mr Mas intends to use them as a negotiating tool, as a distraction from the charge that his administration is incompetent, or as a means to achieve "secession", remains to be seen. What is plain is that the rousing of Catalonia has put the fear of God into Madrid and the governing right-wing Partido Popular. Already there have been dark mutterings from within Spain's armed forces: Catalan independence will not be countenanced.

In this, as in much else, Scotland differs. Inherently wealthy it may be, but it is not as important to the British economy as Catalonia is to the economy of Spain. England and Wales would survive Scottish independence. There are serious fears a recession-wracked Spain, with 26% unemployment, given routinely to extracting 8% of Catalan GDP for distribution elsewhere, could founder if nationalism succeeds.

Catalonia's version of that is also distinctive. In Scotland, Nationalist sentiment is identified, rightly or wrongly, with a single party, the SNP. The Catalans are offered a range of pro-independence parties, left-wing and right-wing. Mr Mas is a conservative, in contrast to the social democrat Alex Salmond, and his CiU coalition remains a minority government. In domestic matters its popularity leaves something to be desired.

Catalonia, in the north-east of the Iberian peninsula, meanwhile has geographical advantages that are a mirror image of Scotland's. Spain's main road and rail links to Europe run through the old kingdom. The importance of that fact has been obvious to Madrid since Franco's day. So Mr Rajoy contemplates the facts as he sees them and sets his face against the kind of referendum even Mr Cameron was wise enough to concede.

A week ago it seemed as though Mr Mas and those prepared to back him might very well win. Bitterness against Madrid, bitterness stretching back to the Civil War and far beyond, has been compounded for Catalans, as they see it, by the abject economic failures of modern central government.

In theory, Catalonia is one of the richest of Spain's semi-autonomous regions. In present reality, bonds issued by the Mas administration are designated as junk; unemployment is relentless; and European aid has been required just to keep the Catalan government afloat. Latent nationalism has been infused, therefore, with the feeling the union called Spain is a failure.

The publication of opinion polls is forbidden in that country in the week before elections. This has left observers guessing. Mass displays at Barcelona's Nou Camp of the white-starred, red and yellow Catalan flag, the estelada, speak of a familiar cultural nationalism. The most recent surveys – to be treated with caution – suggest the ardour of September 11, national day, might have cooled. The Madrid press now believe Mr Mas will fail to win an outright majority.

Second thoughts? The effects of the scaremongering that predicts boycotts of Catalonia's prized sparkling cava? In fact, support for independence seems to have dipped because of one of the paradoxes of modern European nationalism. What becomes of a restored nation's relations, if any, with the EU?

For Catalans, this is important. Some polls have shown support for independence falling by between 10 and 12 points if it puts EU membership at risk. Scotland could be in the paradoxical position of contemplating independence in 2014 as Britain edges towards the European exits. Mr Rajoy and Mr Mas, in contrast, are united in one thing: remaining within the EU club is fundamental.

Some of the latter's statements can even make you wonder what he means by independence. He can't speak highly enough of a federal Europe. He envisages a newly independent Catalonia handing the EU authority for most things bar health, education and welfare. This middle-aged economist certainly sees no prospect for an extravagance such as a Catalan defence force. Some of his followers talk happily of a "United States of Europe".

For certain obvious reasons, the SNP these days would rather not mention Europe at all. But given Catalan attitudes, why would Jose Manuel Barroso, president of the European Commission, insist these eager partners would have to negotiate EU membership from scratch? Mr Barroso, citing the Lisbon treaty, did exactly that at the Ibero-American summit in Cadiz last weekend. Quite how he intended to expel Catalonia's 7.5 million EU citizens was not explained.

The president was mindful, no doubt, of the fact Madrid could yet veto a Catalan application. Some Spanish politicians have made the threat more or less explicit. Is it possible, then, that other countries facing demands for independence would out-source their response to an EU partner? Stranger things have happened.

It would make a nonsense of Europe's human rights charter, the one that guarantees self-determination. If votes are free and fair, it would deny the popular will. Do those count as obstacles? Catalonia will not declare independence tomorrow, in any case, even if nationalism prevails. The best Mr Mas hopes for, amusingly enough, is a referendum in 2014.

Nevertheless, the new Europe's corridors of power are being haunted, suddenly, by some old spectres. Madrid's ham-fisted treatment of the Catalans says some in those corridors have grown afraid.

It comes down to a fundamental question: why are some nations deemed legitimate, worthy or survival, and some are not? More to the point, by what means did anyone gain the right to decide? Catalonia might tomorrow begin to provide one answer.