Catalonia's foreign affairs chief says a controversial referendum on the region's split from Spain "is impossible to stop" despite the central government in Madrid insisting that the vote is illegal and it will not happen.

Raul Romeva made the remarks in an interview with Al Jazeera on Friday, two days before the planned poll on October 1.

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He called on the Spanish government to allow Catalan voters to "solve the situation by democracy" and reassured that "there is not a single reason to believe that there is a risk of violence" on Sunday.

An excerpt of the interview follows below. Watch the video above for Romeva's full discussion with Al Jazeera's Jane Dutton.

Al Jazeera: The central government is Madrid says it will not let the vote to go forward. What is your response to that?

Raul Romeva: My response is that it is impossible to stop that.

First of all, this is not an illegal act; second, this is something that is absolutely necessary in the sense that it provides a political solution to a political problem; and third, it should concern everyone why the repressive response by the state is going that far.

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They are shutting down websites, arresting people, impeding and banning the people from having political debates.

They are violating fundamental rights like the freedom of expression and the freedom of press, so this is something that obviously has nothing to do with the independence of Catalonia - it really has to do with the democratic structures and principles of the Spanish states.

Al Jazeera: How can you guarantee that a vote will not turn violent?

RR: If you have followed all the demonstrations taking place in Catalonia ... you'll see that it's in the DNA of the Catalan way to behave ... always peaceful, even when you have a repressive measure taken by the police.

When they went to the printing houses, when they confiscated election material, the response of the people has always been absolutely peaceful. There is not a single reason to believe that there is a risk of violence.

The question is why somebody is trying to provoke that situation, but obviously from that perspective I have to be very clear: neither from the government, nor from the civil society, the message is to respond to those provocations. On the contrary, our response has always been that it always going to be peaceful.

Al Jazeera: If you look at polls in the lead-up to Sunday's vote, about 40 percent say they will vote for independence. So, is this worth it, considering the fallout whether you win or lose?

RR: This is not about independence, I insist. Eighty percent of the Catalan population understands that given the current situation the solution passes through voting.

Part of the population wants to vote "Yes" and part of it wants to vote "No", which means that, basically, the 80 percent is demanding to solve that situation by democracy, by voting, by listening to everybody and by respecting what the majority wants to have.