BARCELONA, Spain -- A parade of farmers' tractors rolled into Barcelona on Friday in support for Catalonia's independence vote as Catalan and Spanish authorities issued conflicting statements on whether the disputed referendum would even take place on Sunday.

The vehicles, many with Catalan flags, drove slowly into the city to the cheers of residents who stood by the side of the road.

The demand by Catalan separatists to hold an independence vote for the prosperous northeastern region of 7.5 million people has thrown Spain into a political and constitutional crisis.

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Spain's government calls the vote illegal, since it violates the constitution, and the country's Constitutional Court has ordered it suspended. Spanish authorities have been cracking down on efforts to organize the vote, detaining organizers and confiscating ballots and posters.

A farmer gives instructions to farmers on his tractor before marching during a farmers union protest supporting the "Yes" vote in an upcoming referendum on independence in Catalonia, Sept. 29, 2017 in Barcelona, Spain. Getty

The disputed vote has even sparked a showdown over who police in Catalonia should report to, the region's ruling separatist politicians or the central government in Madrid.

European Union officials on Friday ruled out any mediation in the clash.

Catalan regional President Carles Puigdemont and Barcelona Mayor Ada Colau, in separate interviews with The Associated Press, had urged Europe to intervene to break the political deadlock over the vote.

But European Parliament President Antonio Tajani said Friday at an EU summit in Estonia that the dispute is "a Spanish problem in which we can do little. It's a problem of respecting Spanish laws that Spaniards have to resolve."

Tajani says the EU is maintaining its support of Spain's government because "on a legal level, Madrid is right."

"I think it's important to talk on a political level" after the vote, he added.

The EU has said that Catalonia will be ejected from the bloc if it declares independence and would need to apply to rejoin it in a lengthy process that any EU member can veto.

Spain's cabinet spokesman said Friday there will be no referendum on Sunday and warned Catalan officials that they would "face consequences" for pressing ahead with a vote that was suspended by the country's Constitutional Court.

"The government has a constitutional mandate to enforce the laws maintaining civic order," Culture Minister Inigo Mendez de Vigo said Friday during a weekly press briefing. "Nobody is above the laws and whoever violates them will face consequences."

Catalan officials, however, announced that more than 60 percent of the 5.3 million eligible voters are expected to cast ballots Sunday despite the Spanish government's efforts to stop the referendum.

Separatist groups have been calling on parents to organize activities with students in schools this weekend in order to occupy the buildings so Spanish police can't show up to close them off before the vote.

"Catalans will vote - even if somebody takes voting stations by assault and tries to avoid something as natural as placing a voting slip in a ballot," regional vice president Oriol Junqueras told reporters.

Along with two other top Catalan officials, Junqueras displayed for the first time a prototype of the plastic ballot boxes planned for more than 2,300 voting stations.

Acting on a judge's order, Spanish police and civil guard officers have been searching for the ballot boxes for weeks.

Catalan authorities say they will declare independence within 48 hours after announcing the vote's results if the "yes" side wins. The Spanish government has fought the referendum with a myriad of legal actions, including seizing ballots and arresting regional officials.

The unprecedented crackdown has enraged many in Catalonia.

Jordi Marti drives a taxi in Barcelona plastered with stickers supporting the vote. The 63-year-old says the central government in Madrid has kept the prosperous northeastern region in a chokehold for too long.

"And now we have said, 'Game over,'" he told the AP. "It's over because we have been negotiating with the Spanish government for 40 years ... and it hasn't been worthwhile."

With the tourist-popular Barcelona as its regional capital, Catalonia contributes a fifth of Spain's 1.1 trillion-euro economy ($1.32 trillion).

The vast majority of Catalans favor holding a referendum but they have long been almost evenly split over independence itself, with oscillations over the past few years depending on Spain's current economic performance.