In Madrid, the central government of Mariano Rajoy has pledged to fight any move towards independence. There are fears that fellow separatists in the Basque region and even Galicia will follow suit, provoking a constitutional crisis. One association of retired and active members of the military even warned that war should be declared on Catalonia if the region broke away and others have suggested Mas [ Artur Mas, the incumbent regional president and leader of the centre-Right Convergence and Union Party (CIU)] should be tried for treason.