The vote is scheduled for October 1 but the central government in Madrid says the referendum is illegal and can't happen. The fines could be imposed to "fraudulent use", the Spanish agency said, of the data of 5.3 million Catalan voters. This follows a victory by Catalan nationalist forces in the 2015 regional elections that for the first time in Catalonia's history brought to power a coalition of political parties demanding outright independence.
"There is anger at the Spanish government for not allowing an official vote on the matter and for the perceived suppression of a democratic process", says CNBC.
Mr Romeva spoke a day after Catalan regional president Carles Puigdemont accused the European Union of "turning its back" on Catalonia.
Column of tractors in Barcelona, attack on a local police station in a town in Northern Catalonia, war of words between two governments - that is the atmosphere in the Spanish region two days before the referendum.
Catalonia's prosecutor has ordered the regional police - known as the Mossos d'Esquadra - to take control of any voting booths by Saturday, a spokesman for the Madrid government's Catalan delegation said.
An worldwide media watchdog, meanwhile, rebuked the Catalan pro-independence movement for placing undue pressure on journalists to present its side of the dispute. It would also massively diminish Spain as a nation state: Catalonia comprises 16 percent of Spain's population and accounts for 20 percent of its GDP.
These actions have provoked mass demonstrations and drawn accusations from Catalan leaders that the Madrid government was resorting to the repression of the Franco dictatorship. People will demonstrate and show what they think about this situation.More news: How to Get the Most Out of National Coffee Day
This principle was recently upheld by the Spanish Constitutional Court, which called for the referendum to be suspended. Spain and Catalonia are deeply intertwined, conforming a diverse country.
"The declaration of independence has been incorporated into the laws we passed in the Catalan Parliament", Anna Gabriel, head of the CUP, told La Sexta on Tuesday. The Catalan sports minister insists Barca, Espanyol and Girona will have to decide where they want to play after La Liga chief maintains they can not be part of Spain's top flight if the region goes it alone. However, this move, described as a "political atom bomb" could trigger even more backlash in Catalan society.
But those who oppose independence, particularly the Ciudadanos party, believe it is about more than that. The vast majority of countries including France, the USA and Turkey all have said they support a united Spain.
Anyone in possession of the keys or entrance codes to a polling booth could be considered a collaborator to crimes of disobedience, malfeasance and misappropriation of funds, the order said.
The mayor of Barcelona says the European Commission should mediate the tense standoff between the Spanish and Catalan governments over Catalonia's future.
The Spanish government has said so far that it was also open to a discussion, but under the condition that Catalan authorities cancelled the referendum.