A banned Basque nationalist party has blamed the Spanish government for the jailing of their leader Arnaldo Otegi and has called on its supporters to demonstrate against it.
Otegi has been imprisoned on suspicion of belonging to the armed separatist group ETA.
However, he may be released from jail if he can raise 400,000 euros in bail.
Last week the Spanish parliament backed a plan to allow peace talks with ETA if they laid down their arms.
Batasuna spokesman Joseba Permach said that just as the party was starting to put out feelers regarding dialogue, Otegi was arrested.
“It’s a direct attack and slams the door on hopes for a peaceful and democratic solution to the conflict,” he told reporters.
Both the ruling PSOE Socialists and the opposition Popular Party are in agreement over Otegi’s detention.
PSOE spokesman Alfredo Perez Rubalcaba said the Socialists respect the sentence handed out by the judge.
ETA are believed to be behind a car bomb in Madrid yesterday.
Five people were treated in hospital after the explosion and a further 45 were slightly injured.
The group’s campaign for an independent Basque state has been blamed for some 850 deaths since the 1960s.