A divided Spain is voting in its third general election in four years, with all eyes on whether the rise of conservative nationalism will allow the right wing to unseat the incumbent prime minister.

Pedro Sánchez is set to win the most votes, but his Socialists seem far from scoring a majority in parliament to form a government on their own.

The fragmentation of the political landscape is the result of austerity that followed the economic recession, disenchantment with bipartisan politics and the recent rise of far-right populism.

Sánchez called Sunday's ballot after a national budget proposal was rejected in the Lower Chamber by the center-right-conservative opposition and Catalan separatists pressing for self-determination in their northeastern region.

Voting stations opened at 9 a.m. (0700GMT) Sunday and will close at 8 p.m. (1800GMT), with results expected a few hours later.