Next week's "clásico" between Barcelona and Real Madrid was postponed on Friday by the Spanish soccer federation to avoid coinciding with a large separatist rally in riot-stricken Catalonia.
The federation's competitions committee said Barcelona and Madrid have until Monday to decide on another date. If the clubs cannot agree, then the committee will choose.
The Spanish league wanted the match to be moved from Barcelona to Madrid because of security concerns, with the return match automatically switched from Madrid to Barcelona. But the competitions committee rejected that idea, saying that it was against its rules to invert the order of the games.
The federation, in consultation with government officials, said Thursday it wasn't safe to play on the same day as the rally.
The Spanish league runs the top two soccer divisions in the country, while the federation controls regulations and matches for professional and amateur games.
The northeastern Catalonia region has seen violent protests for the last few days with police clashing with protesters angered by a Supreme Court decision to sentence nine separatist leaders to prison. Separatist groups have called for supporters to rally in Barcelona on Oct. 26, the original date of the match.
There appear to have been fears that protests could again get out of hand and make access difficult to the Camp Nou.
Catalan independence flags are a regular feature at Barcelona's home games, as are collective shouts for "independence" by separatist supporters.
About half of Catalonia's 7.5 million residents support a break with Spain, according to polls.