Whipped up in a pro-independence fervour, millions of Catalans vote Sunday in a snap election that could result in a redrawing of the map of Spain.
Artur Mas, president of the northeastern region, is promising a referendum on self-determination if the vote goes his way.
Even as Catalan independence flags flutter from balconies in the northeastern region's capital, Barcelona, however, analysts say a breakup of recession-torn Spain remains a distant prospect.
Spanish Prime Minister Mariano Rajoy's right-leaning government is determined to thwart any referendum, saying it flies in the face of common sense, and vowing to wield the national constitution if necessary.
But the vote may drive a wedge into the eurozone's fourth largest economy as it fights the deepest economic crisis since the return of democracy after the death in 1975 of General Francisco Franco.
The secessionist movement could also be hard to stop.
At Mas' last campaign rally on Friday 18,000 people crammed into a Barcelona stadium, chanting "Independence!" in unison and brandishing a sea of Catalan and European Union flags.
"We are not vassals of the Spanish state," the 56-year-old, bespectacled Catalan leader declared to delighted supporters.
It is a cause that stirs strong emotions in Catalonia, which traces its history back more than a millennium.
The region was welded to Spain at the nation's symbolic birth when Queen Isabella of Castile and King Ferdinand of Aragon, which included Catalonia, married in 1469.
Now the region of 7.5 million people accounts for more than one-fifth of Spain's economic output, a quarter of its exports, and one of the world's greatest football teams, Barcelona FC.
But Catalonia also has 44 billion euros worth of debt, equal to one-fifth of its output, and was forced to go cap in hand to Madrid this year for more than five billion euros to help make the payments.
A growing sentiment that Spain is the cause of Catalonia's financial troubles is at the heart of the national split.
Mas accuses Madrid of raising far more in Catalan taxes than it returns and estimates the gap at 16 billion euros ($21 billion) a year, a figure Madrid disputes.
Emboldened by huge protests in Barcelona demanding independence on Catalonia's national day, September 11, Mas demanded greater taxing powers from Rajoy.
When he did not get the concessions he was seeking, he called the snap election.
The resentment over finances has fanned the flames of independence in Catalonia, a region proud of its language and culture that has been forced to slash spending on schools, universities and hospitals.
The Catalan leader is widely suspected of using the secessionist cause as leverage for votes in an election he called two years early, and to squeeze more cash out of Madrid.
"Even Mas seems to be cautious in calling for the region's full autonomy," said a report by London-based IHS Global Insight analyst Blanka Kolenikova and economist Raj Badiani.
"Such a prospect would indeed open Pandora's Box, including a constitutional crisis in Spain; possible contagion to other peripheral regions with sovereignty aspirations; a blow to Spain's public finances; but also questions over whether a Catalan state, alongside Spain and within the European Union would be viable," it said.
Indeed, Mas' nationalist coalition, Convergence and Union, has traditionally been a force of moderation and the regional boss has carefully skirted using the word 'independence'.
Latest polls show Mas' alliance heading for a win but falling short of the absolute majority he is seeking.
Surveys a week before the vote showed Mas' alliance taking 60-64 of the 135 seats in parliament, not far from the 62 it now holds, with Rajoy's Popular Party and the opposition Socialists fighting for second place.
Nevertheless, pro-referendum parties are widely expected to enjoy a majority in the new parliament.
If there was a referendum on "self-determination," Catalans would vote in favour by 46 percent to 42 percent, according to a survey in leading daily El Pais.
At one Catalan hamlet, Gallifa, the mayor has already stopped sending some taxes directly to Madrid, delivering them instead to Barcelona in a symbolic gesture of independence.
In the village, 61-year-old farmer Josep Casas watched over his cows.
"I have never felt Spanish. This is one more step," he said.
"I am a farmer. I know you have to keep sowing the seeds and then we will see if there's a harvest or not."