Jordi Marti's taxi is black-and-yellow, like all of Barcelona's official taxis, but it isn't hard to spot.

It is plastered with stickers supporting Sunday's planned referendum on Catalan independence and festooned with other symbols of the Catalonia region's desire for statehood.

Marti, a stocky 63-year-old with close-cropped hair, is a fervent supporter of Catalan nationalism. He sees the vote on whether to break away from Spain as a chance for his long-held dream of a Catalan republic to become real.

Spain's Madrid-based government has kept the prosperous northeastern region in a chokehold for too long, he said.

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

With an easy smile and a warm manner, Marti yells to passers-by on the sidewalk, asking them how they intend to vote and encouraging them to choose independence.

The banter is good-natured, even when some people tell him they're not sure how they will vote or say they are reluctant to back independence for Catalonia, a region with its own language and cultural traditions.

Marti has been a taxi driver for eight years after a life of odd-jobbing around the world. He loves his work and decided his taxi was an ideal platform to advance his ambitions for an independent Catalonia.

With a population of 7.5 million inhabitants, Catalonia contributes a fifth of Spain's 1.1 trillion-euro ($1.32 trillion) economy.

The central government is doing all it can to prevent the weekend vote. It has declared the referendum illegal. Spain's Constitutional Court has ordered balloting to be suspended while judges consider if the referendum is lawful.

Catalan officials say it will happen anyway.

Marti is encouraged by the surge of support among young people for the referendum and for a "yes" vote supporting secession. They are fired up, just like he is.

"At the end of the day, all the movements for change have to come from below," he said.

Spotting students engaged in a noisy street protest, Marti pulls a broad pro-independence flag from his taxi's trunk, ties it to a long fishing rod and joins them in their demand to be heard.