To mark National Catalan day on Wednesday, Catalan separatists will attempt a 250 mile human chain along the coastline of the Catalonia region, in north-east Spain. This demonstration is part of the continued bid for a referendum for independence from Spain, which is strongly opposed by the Spanish government.

Around 400,000 people have already signed up to take part in the demonstration, which has been organised by the Catalan National Assembly, the biggest pro-independence group in the region.

At exactly 5.14pm local time (4.14pm) – to represent the year 1714, when Catalonia finally lost its independence, all the participants will symbolically join hands. More chains have been planned in other

Catalan-speaking territories, such as Valencia (where the Spanish government has forbidden it), the Balearic Islands and south-east France.

If you're planning to take part, or know people who are, we'd like to see your pictures and videos. We're interested in the preparations for the event as well as the human chain itself. You can submit pictures and videos by clicking the blue 'contribute' button – or you can download the free GuardianWitness smartphone app and share your content from wherever you are.

We will publish the best pictures and videos on the site.

Si tens planejat participar en la Via Catalana, o coneixes algú que hi vulgui participar, ens agradaria veure les vostres fotos i vídeos. Ens interessen tant els preparatius per a l'acte com la cadena humana en si. Podeu enviar fotos i vídeos fent clic al botó blau 'contribute' - o us podeu descarregar l'aplicació gratuïta per a smartphones GuardianWitness i compartir els vostres continguts des d'allà on sigueu.

Publicarem les millors fotografies i vídeos a la pàgina web.