Protesters begin arriving in Barcelona for National Day demo

With two hours to go until the start of the demonstration calling for a Catalan Republic on Catalonia's National Day on Tuesday, central Barcelona had already begun to fill up with participants, many of whom had traveled in from places all over the country.

The protest in favor of independence, due to start at 17:14 hours - 1714 being the year that Catalonia lost it sovereignty in the War of the Spanish Succession - will stretch some six kilometers through the Catalan capital, from Glòries square to the Diagonal avenue.

Split into 37 sections, with each person allocated a particular stretch, a rocket will mark the start of the demonstration. The idea is for the participants to create a wave of sound, moving from section to section, while people hold up banners and make their voices heard.

Once the wave of sound has made its way along the entire demonstration, it will reach a wall and causing it to fall, as a metaphor for the power of the citizens to overcome obstacles and achieve the ultimate aim of making the Catalan Republic a reality.