MADRID (Reuters) - Spain's Constitutional Court on Tuesday partially struck down a sovereignty claim approved by lawmakers last year in the northern region of Catalonia, a vital step toward a referendum on full independence, court papers showed. 
 
 In January 2013, Catalonia's regional parliament unanimously adopted a declaration of self-determination saying the people had the right to vote on breaking away from the rest of Spain. 
 
 The Madrid court declared "null and unconstitutional" the first point in the Catalan ruling which said the people of the region had the legal right to infringe the Spanish constitution. 
 
 Catalan President Artur Mas has promised to hold a referendum on secession from Spain on November 9, saying Catalonia should be a separate state within the European Union and the euro zone. 
 
 Spanish Prime Minister Mariano Rajoy says such a vote would be unconstitutional. 
 
 Mas has been buoyed by a groundswell of public support for the referendum but with the European Union and Spanish government firmly opposed, full independence seems unlikely. 
 
 The Catalan Parliament in Barcelona voted in January to send a petition to the national legislature seeking the power to call a popular vote on the region's future. That initiative is still pending a vote in Madrid. 
 
 Under the constitution of 1978, Catalonia, worth a fifth of Spain's economic output, has significant autonomy. But perceptions that the taxation system, which spreads wealth between the regions, is unfair have fuelled the rising independence movement. 
 
 Mas has suggested that once all legal roads are exhausted, he will use Catalonia's next election in 2016 as a proxy vote on the issue. Opinion polls show more than half of all people from the region support secession from the rest of Spain. 
 
 (Reporting by Teresa Medrano, Writing by Paul Day; Editing by Janet Lawrence) 

 Madrid (AFP) - Spanish judges ruled Tuesday that a planned independence referendum in Catalonia was illegal, dealing a blow to the indebted region's drive for self-rule. 
 
 The northeastern region vowed to push on with the vote, however, defying fierce resistance from the national government, which has called for unity as Spain crawls out of its economic crisis. 
 
 Under Spain's constitution a region "cannot unilaterally call a referendum on self-determination to decide on its integration in Spain", according to a written summary of the ruling released by the Constitutional Court. 
 
 It ruled "unconstitutional and null" a declaration by the Catalan regional parliament which claimed Catalonia had a sovereign right to hold a vote on its future. 
 
 The court upheld a legal challenge by the national government to that declaration and said any "right to decide" by Catalans could only be exercised in accordance with Spain's 1978 constitution, which insists on the unity of Spain. 
 
 Leaders in Catalonia have called the referendum for November 9 to ask Catalans whether their region should be a separate, independent state. 
 
 Many Catalans have drawn a comparison with Scotland, whose leaders are holding a referendum in September on independence from Britain -- a move authorised by the British government. 
 
 Spain's conservative Prime Minister Mariano Rajoy has argued that Catalonia cannot hold a referendum like Scotland because Spain, unlike Britain, has a written constitution that rules out such a move. 
 
 Rajoy insisted last month that the referendum "can't take place". 
 
 "No one can unilaterally deprive the entire Spanish people of the right to decide on their future," he told the national parliament, which is due to debate the referendum issue on April 8. 
 
 Tuesday's ruling poses a setback for Catalonia's president Artur Mas, who has said he is determined to hold the vote legally. 
 
 The Catalan government insisted shortly after the ruling that it would not derail the drive for a referendum, however. 
 
 "This will have no effect on the process," its spokesman Francesc Homs said on Catalan television. 
 
 - 'We will not budge' - 
 
 The leftwing ERC party, one of the rival groupings that united with Mas in calling the referendum, echoed that defiant note. 
 
 "We will not budge from our commitment to hold polls on November 9," its parliamentary spokesman Pere Aragones said in a statement. 
 
 The referendum is opposed by Spain's two largest national parties: the ruling conservative Popular Party and the main opposition Socialist Party. 
 
 Proud of their distinct language and culture and fed up after five years of stop-start recession, many in Catalonia want to redraw the map of Spain, saying they feel short-changed by the central government, which redistributes their taxes. 
 
 Catalonia is home to 7.5 million of Spain's total population of 46 million people. It accounts for more than a fifth of Spain's economic output and a quarter of its exports. 
 
 On September 11 last year, Catalonia's national day, hundreds of thousands of Catalans massed in a vast human chain stretching across the region to demand independence. 
 
 The national day recalls the conquest of Barcelona by Spanish king Philip V's forces in 1714. 
 
 Catalonia was there at the symbolic birth of Spain when Queen Isabella of Castile and King Ferdinand of Aragon, a region that included Catalonia, married in 1469.
– More secessionist rumblings: Catalonia is technically a largely autonomous "community" in northeastern Spain. It would like to be much less than that. The region's parliament last year decided that it would hold a referendum on secession, something it says it fully intends to do on Nov. 9—even though Spain's Constitutional Court yesterday ruled such a move illegal, reports AFP. Catalonia's president wants to see it become its own EU state, something the EU is also not on board with, reports Reuters. The court's ruling stated that a region "cannot unilaterally call a referendum on self-determination to decide on its integration in Spain," and therefore dubbed parliament's assertion of its right to hold such a vote "unconstitutional and null." The country's PM says any comparisons between Catalonia's situation and Scotland's are moot, because Britain has no constitution barring Scotland from holding a similar referendum. One of the roots of the secessionist bid: money. Catalonia is home to about a sixth of the country's people but makes up a fifth of its economic output, and has taken issue with how Spain's taxation system divvies up wealth between the various regions. (Also making a secession bid: Venice.)