SANT PERE DE TORELLO, Spain—Prime Minister Mariano Rajoy faces Spain’s biggest constitutional crisis in decades after Sunday’s violence-marred independence referendum in Catalonia opened the door for its wealthiest region to move for secession as early as this week.
The streets of Barcelona, the Catalan capital, were quiet on Monday, but newspaper editorials said the referendum, in which Catalan officials said 90 percent of voters had chosen to leave Spain, had set the stage for a decisive clash between Madrid and the region.
