The league released a statement shortly after the federation confirmed Dec. 18, a Wednesday, as the new date. The match was initially scheduled for Saturday but was postponed because of a planned separatist rally in the riot-stricken Catalan capital.
The new date was proposed by the clubs, but the league wanted the match to be played on Dec. 7, a Saturday, because it would better suit television rights holders. In addition, Copa del Rey matches are scheduled for Dec. 18, and the Club World Cup will already be underway in Qatar.
The "clásicos" are the biggest games of the year in Spain and are among the most watched matches in the world. The league usually promotes one of them to the Asian market and the other to the American market.
Saturday's match would have been played at 1 p.m. local time (1500 GMT), a timeslot that favors Asian audiences. If played in the middle of the week, the game will most likely have to start at night, possibly creating problems for the league to abide to its contracts with the rights holders.
The dispute over the "clásico" adds strain to the relationship between the league and the Spanish federation. League president Javier Tebas and federation head Luis Rubiales — two outspoken figures in Spanish soccer — have been at odds over a series of issues recently. One of them is the league's attempt to play a regular-season match in the United States, something the federation has yet to approve.
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 league said it is studying what actions it can take to keep the "clásico" from being played on Dec. 18. It said it will make a decision after gaining access to the reports and documents the federation used to make the change.
The league initially wanted the match to be moved from Barcelona to Madrid, with the return match automatically switched from the Spanish capital to Barcelona. But the federation's competitions committee rejected that idea, saying it was against its rules to invert the order of games.
The federation had asked the clubs to propose a new date after it was agreed that it wasn't safe to play on Saturday as scheduled. The northeastern Catalonia region has been rocked by violent protests since the Supreme Court ruled to sentence nine separatist leaders to prison.
Catalan independence flags are a regular feature at Barcelona's home games, as are collective shouts for "independence" by separatist supporters.
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