Prosecutors in Catalonia have ordered police to seize ballot boxes, election flyers or any item that could be used in a banned independence referendum called by the Spanish region's separatist executive.
The tennis champ has waded into the political row and slammed plans for a referendum.
A new book provides valuable insight into how a surge of separatist feeling has gripped Catalonia and put it on a collision course with Madrid.
Tensions are mounting along the EU's only land borders with Africa on the Moroccan coast.
Catalan youths, who have grown up during a time of surging support for independence, turned out in droves for a huge rally on Monday to demand their region break away from Spain.