Spain's ruling Socialists face their first electoral test Sunday since the nation plunged into recession, with the prime minister's party seeking a historic win in Basque Country regional polls.
The regional elections in the Basque Country and Galicia come after Spain saw a decade-long real estate boom collapse and the country fall into recession late last year.
Prime Minister Jose Luis Rodriguez Zapatero's Socialists are hoping to remain part of the governing coalition in Galicia and score a historic victory in the Basque Country, a separatist-minded region bordering France.
A poor showing in the polls by the main opposition Popular Party (PP) meanwhile could lead to renewed calls for the resignation of its leader Mariano Rajoy.
Rajoy has struggled with infighting since he led the party to its second straight general election loss in March 2008.
Polls show the Socialist Party is poised to make big gains in the Basque Country and is neck-in-neck with the moderately nationalist Basque Nationalist Party (PNV), in power since 1980.
If the party wins outright, or is able to form a coalition, it would be the first time since the nation returned to democracy in 1975 that the Basque Country would be governed by a party that unquestionably backs keeping the region as part of Spain.
Analysts credit the rise in support for the Socialists in part to Zapatero's bid during his first term to negotiate peace with the armed Basque separatist group ETA, blamed for 825 deaths in its 40-year campaign for an independent Basque homeland.
Those negotiations eventually failed and the group resumed its attacks.
If no party wins an outright majority in the 75-seat Basque regional assembly, polls show most Basques would prefer to see a coalition formed between the Socialists and the PNV.
"Basque society does not want any adventures and for this reason it prefers an alliance that would require the PNV and the Socialists to get along," the director of Basque polling firm Euskobarometro, Francisco Jose Llera, told AFP.
In the rugged northwestern region of Galicia, the Socialists are looking to hold on to the power they won in 2005.
The region had previously seen 16 years of rule by the PP under Manuel Fraga, a former information minister in Francisco Franco's long dictatorship.
Rajoy has campaigned heavily in his home region but his campaign has been overshadowed by allegations of corruption in Madrid and several other regions involving businessmen close to the PP.
The corruption scandal has also tarnished the Socialists as Justice Minister Mariano Fernandez Bermejo resigned on Monday after it was revealed that he had gone on a hunting trip with the judge leading the probe into the affair.
The PP had accused the minister of interference.
The Socialists currently rule Galicia in a coalition with the Galician Nationalist Bloc (BNG), a coalition of political parties.
Saturday is an official "day of reflection" for the vote and no campaigning can take place.
More than four million people are eligible to vote in Sunday's polls.