At least 1.4 million of Catalans have filled the streets of Barcelona, calling for secession from Spain, as the region prepares to go to the polls in what local politicians say will serve as a proxy vote for independence.

The rally’s organizers said that up to 2 million demonstrators took to the streets of Barcelona, while the Catalan news agency (CNA) put the figure at 1.4 million people.

“We see the immense capacity of the mobilization of our people, who want to be listened to. We want the world to see that,” the leader of the ‘Junts pel Sí’ (Together for Yes) coalition, Raul Romeva, said, as cited by CNA.

The massive pro-independence rally, dubbed “Gateway to the Catalan Republic” (Via Lliure cap a la República Catalana), took place on Catalonia’s national Day, September 11.

Jordi Sanchez, the president of the Catalan National Assembly (ANC) said he believed the rally will be one of the largest in Catalonia’s history.

The demonstrators, who marched under banners bearing the slogan "Let's start building a new country" came to Barcelona from all parts of Catalonia by car, buses and rail.

The rally stretched along one of the city’s main avenues.

In the late afternoon, people started filling the streets of Barcelona for the march that was scheduled to start at 17:14 (15:14 GMT) local time, referring to the year 1714 when Barcelona was defeated by Bourbon troops. The Catalans lost their independence and sovereignty to Spanish and French forces in the War of the Spanish Succession on September 11 of that year. Since 1886, it has been celebrated as the National Day of Catalonia, or Diada in Spanish.

El punter gegant ha recorregut els 135 trams i ha arribat al Parlament de Catalunya! #SomViaLliurehttps://t.co/T3Nskvivda — Assemblea Nacional (@assemblea) September 11, 2015

A giant arrow pointer, symbolizing the way to the Catalan Republic, was carried along Meridiana Avenue. The march started at Roselló Porcel Street, considered the entrance to Barcelona, and continued all the way up to the Catalan parliament located in Parc de la Ciutadella.

La independència parla de futur i apunta cap a una societat més justa, oberta i inclusiva #WeAreCataloniapic.twitter.com/Bn7BBlTNVs — Assemblea Nacional (@assemblea) September 11, 2015

Along its route, the yellow arrow sign was welcomed by crowds shouting “independencia”.

The arrow reached the parliament at 18:00.

The demonstration took place on the same day as the kick off of an electoral campaign that has been framed as a de facto vote on the region’s secession from the rest of Spain. Catalonia’s regional election is to take place on September 27.

The “Together for Yes” (‘Junts pel Sí’) coalition is expected to win a majority of at least 68 seats in the 135-seat regional assembly.

Catalan President Artur Mas said on Friday that he would rather count “votes instead of seats,” but “all attempts to organize a referendum have been blocked” by the Spanish government, CNA reported.

Mas, who is running with “Together for Yes,” said the election is the “only legal option” left to Catalonia to find out how many people are in favor of independence.

“If we win, if we have a majority of MPs, we will be open to negotiate with Madrid, Brussels and all European capitals in order to get an agreement. We’ll have a positive attitude,” he said.

READ MORE: Catalan president vows new independence push after projected parliamentary majority

The organizers said Friday’s rally is an attempt to show the will of the vast majority of the Catalan people and a last plea for a referendum on independence from Spain. The demonstration is “to be the last one with a vindicatory purpose,” said Carme Forcadell, former president of the ANC.

While Madrid refused to comment on the Friday’s demonstration in Barcelona, Spanish Prime Minister Mariano Rajoy’s deputy called it an “electoral event” for Catalan President Artur Mas, according to CNA.

Historically Catalonia has been one of Spain’s better-off regions, accounting for one-fifth of the country’s economic output. The local population has been dissatisfied with their taxes being used by Madrid to support poorer areas of the country.

Spanish Prime Minister Mariano Rajoy has said that Catalonia’s secession would be illegal, while EU officials have warned Catalonia that it would have to leave the bloc if it seceded.