Kim Hjelmgaard

USA TODAY

The Spanish region of Catalonia could briefly steal the referendum limelight from Scotland on Thursday during demonstrations in Barcelona aimed at sparking momentum for those opposed to Spanish rule.

About 55% of Catalans support independence from Spain, according to the Public Diplomacy Council of Catalonia, a government-supported group that seeks to raise awareness about the semiautonomous area of Spain that has Barcelona as its capital.

The organizers of Catalan Way 2014, as Thursday's mass demonstration is called, expect more than 450,000 people to attend and hope to fill the streets and ballot boxes.

A similar event last year brought 1.5 million people together across Catalonia to campaign for independence. The date marks the anniversary of when Catalonia lost its independence by succumbing to a year-long Spanish military siege in 1714. On Sept. 11 of that year, Catalonia became a province of the Spanish crown, which it has been for 300 years.

Catalonia's 7.5 million residents have their own language and culture, and the region represents around one-fifth of Spain's $1.4 trillion economy. Unlike in Scotland, Catalans have not been granted a legally binding referendum on independence.

Spanish Prime Minister Mariano Rajoy has said on many occasions, most recently in July, that a vote "cannot and will not take place," and he is prepared to challenge the issue aggressively in Spain's constitutional courts.

He has cautioned — as Scotland's independence naysayers have — that a Catalonia untethered from Spain would have to renegotiate dozens, if not hundreds, of important international relationships, including with the European Union and NATO.

That hasn't stopped Artur Mas, Catalonia's president, from seeking formal independence consultations that would lead to a referendum vote Nov. 9.

"Catalans want to vote. We want to vote in order to become the masters of our own future and to be able to decide how to best respond to the needs of our fellow citizens. We are not moved by the desire to be better than others, but by the desire that we may become better ourselves," Mas said Wednesday in a statement.

"I would also like to take a moment to be explicitly clear with the central government and the institutions of the Spanish state: There is still time to listen to the Catalan people's peaceful and democratic outcry," Mas said.

Albert Royo-Mariné, secretary general of the Public Diplomacy Council, said Spain should take note of Scotland's vote and "the way Britain managed to find a way to give the people of Scotland a vote that mirrors their political will."

"Scotland has been given the opportunity to choose what they want to be, and Spain needs to be inspired by this precedent. This is the way to solve political conflicts," Royo-Mariné said. "Spain is a young democracy, and it cannot afford to block a peaceful movement such as this. That would be dangerous for Spain."

Spanish government bond prices have fallen in recent days amid Catalonia's push for independence.

Susana Beltran, vice president of Catalan Civil Society, an anti-independence group, told Agence France-Press that Scotland and Catalonia are "two different realities." She said, "Catalonia is a region, not a nation like Scotland."