Hundreds of people staged a sit-in at Barcelona's train station on Sunday in support of 12 jailed Catalan separatist leaders.
They sang the Catalan regional anthem and chanted: "We are peaceful people." Riot police formed a line around the protesters and removed some of them from the station.
The leaders are likely to be sentenced by Spain's Supreme Court on Monday.
Nine of the 12 Catalan politicians and civic leaders have been in pre-trial detention for close to two years.
A source in the judiciary told Reuters news agency on Saturday that some are likely to receive 15-year sentences for sedition but the more serious charge of rebellion is likely to be dropped.
The charges relate to their role in the illegal independence referendum which was held two years ago and the short-lived declaration of independence that followed.