Madrid (AFP) – The head of the Spanish soccer league warned on Monday that champions Barcelona could not play in Spain’s La Liga if Catalan nationalists succeeded in making their region independent.

“The law of sport is very clear: the only non-Spanish competitors are the Andorran clubs” from the small neighboring principality, said Javier Tebas, president of the Spanish Professional Football League.

If Catalonia broke away from Spain, as nationalists have vowed to do if they win Sunday’s regional election, La Liga “would be a league without Catalan clubs,” he told Spanish television.

As well as Barca and its soccer, basketball and handball teams, such an exclusion would affect others such as Espanyol, the other big top division side from Barcelona.

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Catalan nationalist leaders have vowed to declare independence within 18 months if they win the vote on Sept. 27. Polls show they may win a majority in the regional parliament.