Following a six-month political impasse, these are the first repeat elections in Spain’s history, likely to spell an end to the nation’s traditional two-party system.
 
Polls suggest that no party will be able to gain enough seats to form a single-party government; but the anti-austerity Unidos Podemos is likely to overtake the centre-left Socialist Party as the second largest party. The ruling conservative Popular Party is expected to come first, with the centrist Ciudadanos also in the parliament.
 
Analysts expect intense coalition talks between all four parties in the coming month, with the possibility of a third election not ruled out.