MADRID | The Corner | There is nothing better than politics to add volatility to the markets. After Catalan leader Artur Mas formally convoked a Nov. 9 referendum for Catalonia independence, the Spanish government is holding an emergency cabinet meeting Monday to launch a lawsuit aimed at blocking the vote. In the short term this clash could widen spreads in Spain and affect domestic banks with exposure to Catalonia, Morgan Stanley pointed out. The most probable scenario is a fiscal agreement, they believe.