Translate the following English sentence to French:
"The reasons for the large demonstration organised by the trade union movement at the Feira Summit are therefore understandable and the fact that tens of thousands of people took part in this demonstration definitely made it one of the most striking features of the Summit."
On comprend donc l'importante manifestation du mouvement syndical à l'occasion du Conseil de Feira, manifestation qui, en raison du nombre élevé de participants ­ des dizaines de milliers ­, est assurément devenue un des événements les plus marquants de ce sommet.