[JURIST] Spain's Constitutional Court [official website] unanimously ruled [judgment, PDF, in Spanish] Tuesday that Catalonia's referendum on independence was illegal as the regional law upon which it was based was illegal under Spain's Constitution.
Spain's Constitution [text, PDF] prohibits any region in Spain from seceding and mandates that all Spanish citizens must have a voice in the country's national sovereignty. Earlier this month, the court ordered [JURIST report] the suspension of Catalonia's planned parliamentary session on independence next week warning of prosecution if they proceeded with the session.
Catalan officials have spoken out [NYT report] over secession failures and the jailing of regional officials [JURIST report] as "repression over dialogue." Since the jailing of pro-independence leaders on Monday, protests have arisen across the country. The Catalan government has asked the EU [Telegraph report] to help with the conflict stating that the jailing of the two independence leaders is "an attack on fundamental rights."