The northeast Spanish region of Catalonia is voting for president and a regional parliament Sunday in elections considered a barometer of rising independence sentiment.

Independence is not on the ballot Sunday, but the incumbent Catalan president, Artur Mas, is expected to be re-elected and has vowed to hold a referendum on self-determination in his next term.

The Spanish government in Madrid vows to block any referendum, arguing that the constitution does not permit a region alone to decide its independence.

The elections come amidst a debt crisis and economic stagnation in much of the eurozone, especially Spain, and in its 17 regions, including Catalonia, which is the most important region economically.

Last September 11, an estimated 1.5 million people -- 20% of Catalonia's population -- filled the streets of Barcelona, the Catalan capital and Spain's second largest-city, demanding independence...

...Catalonia has its own flag and language, and various analysts say the economic crisis has brought long-simmering nationalist sentiment to the forefront.

Polling places are open from 9 a.m. to 8 p.m. Sunday (3 a.m. to 2 p.m. ET Sunday).