The Clasico between Barcelona and Real Madrid, Spain's biggest football match, has been postponed due to protests in Catalonia, the Spanish Football Federation (RFEF) announced on Friday.
The two clubs have until 10:00am (0800 GMT) on Monday to find a new date, which will be decided by the RFEF if they cannot reach an agreement.
The original fixture was due to take place at Barca's Camp Nou on October 26.
"FC Barcelona and Real Madrid must agree on the new date of the meeting before October 21," an RFEF statement read.
"In case of not reaching an agreement, the Competition Committee will be responsible for determining the date of the meeting."