The referendum has divded Spain with Madrid branding the vote “illegal” and threatening to arrest voters and officials.
Catalan President Carles Puigdemont has called on Catalans to actpeacefully during Sunday’s referendum as thousands descend on Barcelona Town Hall on the eve of the poll.
Despite the threats from Madrid, Mr Puigdemont has said it will carry out the vote no matter what.
With the two sides seemingly on collision course the potential for outbreaks of violence is a realistic possibility with the local police ordered to close down the polling stations and stop people from voting.
Mr Puigdemont said the pro-independence supporters would not “step back one millimetre” in their commitment to carrying out the referendum, in an interview with Eldiario.es, and insisted everything is in place for people to vote.
But he added if people did have problems voting, then “don’t do anything violent. This movement is pacifist.”
Mr Puigdemont said he would defend the referendum cause to the end and in an apparent reference to the possibility that he could be arrested, added: “no matter the consequences”.
The Catalan leader said he was very angry with the State Attorney General, José Manuel Maza, for not ruling out the possibility of arresting him: “I am upset that he says I can be detained for my political ideas”.
Mr Puigdemont admitted the parliamentary path that has been followed up to October 1, the date of the referendum, is not the one he wanted, but said it is “the only one” possible.
The leader blamed the constant obstacles of the central government for refusing to engage in talks with the regional government.
Reflecting on the statement of US President Donald Trump who said he was in favour of a united Spain, Mr Puigdemont said: “It is evident that any state that is asked today about this issue will support the position of Spain.”
Looking ahead to the situation in Catalonia after the vote, Mr Puigdemont said: “There will be, not an immediate change, but I think at least Europe should stop looking the other away and thinking that this it’s just an internal matter.”
Police have been ordered to ensure the polling stations – mostly in schools – are closed by 6am on Sunday, before the voting is due to start at 9am.
But many are already occupied by supporters who are vowing to keep the buildings open to ensure the vote goes ahead.
Police will remove people from the polling stations on Sunday, a government source said on Saturday, without giving details on how this would be carried out.
The source added it would be up to the police how they remove people.
Volunteers staffing polling stations and using the national census in Sunday’s banned Catalan referendum on independence from Spain will be liable for fines of up to £264,500 (€300,000).
Meanwhile, Catalonia’s High Court ordered Google to delete a smartphone application that the Catalan government was using to spread information about the vote. A company spokeswoman said Google removes content when it receives a court order.