Spain's Supreme Court on Wednesday decided not to legalize a new Basque separatist party, considering that it had not sufficiently distanced itself from the violence of the armed separatist group ETA, dpa reported.
The ruling keeps the party, called Sortu, from contesting Basque local elections in May.
The court sided with Prime Minister Jose Luis Rodriguez Zapatero's government, whose lawyers argued that Sortu was a successor of ETA's political wing, Batasuna, which was outlawed in 2003.
Sortu, which was launched in February, took the unprecedented step of openly criticizing the violence of ETA.
The Spanish government, however, regarded the criticism as just a ploy to make it possible for radical separatists to participate in Basque political life.
ETA, which has killed about 850 people since 1968, has observed a ceasefire since September.