(dpa) - Spain's Socialist Prime Minister Jose Luis Rodriguez Zapatero was Monday seen as facing complicated negotiations to form his second government after being re-elected short of an absolute majority in Sunday's parliamentary elections.
The Socialists clearly defeated the opposition conservative People's Party (PP), but will need to continue relying on the support of small regionalist and leftist parties, editorials said.
The negotiations will not be made easier by the weakening of the small parties, which lost representation to the two main parties in a sign of the increasing bi-polarization of Spanish politics.
The Socialists took 44 per cent of the vote and 169 seats in the 350-strong parliament, up from 164 seats in 2004, with nearly all votes counted.
The PP reaped 40 per cent and 153 seats, up from 148 seats four years ago.
The PP's result remained clearly short of what the party had hoped for, and cast uncertainty over the future of party leader Mariano Rajoy, whose confrontational tactics and lacklustre style had been criticized during the campaign.
The biggest losers, however, were the small parties, among which the Catalan separatist party ERC and the far-left Izquierda Unida will no longer have their own parliamentary groups after only taking 3 and 2 seats respectively.
The best smaller performers were Catalan regionalist formation CiU, with 11 seats, and the Basque Nationalist Party (PNV) with 6 seats.
The Socialists were likely to find it difficult to form an alliance with CiU, which competes with the Catalan branch of the Socialist Party that governs the north-eastern region, the daily El Mundo observed.
The Basques and Catalans were expected to demand more self-government for their regions in exchange for their eventual support, a plan that could create tension between the government and the conservative opposition.
Zapatero on Sunday pledged to seek to improve the spiteful relations between the government and the PP, which has waged a merciless opposition after suffering a surprise defeat to the Socialists in 2004.
The 2004 result was believed to have been influenced by Islamist train bombings that killed 191 people in Madrid three days before the vote.
Sunday's elections were also overshadowed by bloodshed, with the militant Basque separatist group ETA gunning down a former Socialist councillor in the Basque town of Arrasate two days before the poll.
The killing was believed to have helped the Socialists by prompting more of their supporters to use their right to vote.
The fight against ETA has been one of the main points of disagreement between the government and the PP, which condemned Zapatero's unsuccessful attempt to negotiate with ETA, accusing him of being lenient on terrorists.
In addition to the continuing challenge of ETA, which killed five people during Zapatero's first legislature, the new government will have to deal with a slowing economy.
Zapatero would have to take unpopular measures to stem a rising inflation and unemployment rate, commentators said.