Spanish Prime Minister Mariano Rajoy plans to prioritize talks with the Socialist Workers' Party after his centre-right People's Party (PP) won the most seats in parliamentary elections.
The PP beat projections and won 137 seats in the 350-seat parliament on Sunday to maintain its position as the strongest party in the country. But Rajoy's party is still short an absolute majority and will have to seek a partner in order to form a government.
"I will hold talks with all political powers, but first with the PSOE," Rajoy told radio broadcaster Cadena Cope on Monday, referring to the Socialist Workers' Party.
"We need the support of the socialists on fundamental issues," the conservative premier added.
The PSOE, the country's other biggest political force, has long rejected the prospect of a coalition with the conservatives.
Deputy party chief Cesar Luena reaffirmed this sentiment on Monday, telling Spanish broadcaster Cadena Ser that the PSOE would "neither actively nor passively" support Rajoy's re-election.
The conservatives have had trouble finding a coalition partner due to a string of corruption scandals that continue to plague the party.
Sunday's elections were held six months after a vote in December left Spain in political paralysis, with the four largest parties unable to agree on a coalition government.
The EU is counting on Spain, the eurozone's fourth-largest economy, to form a stable government as quickly as possible in order to avoid any further uncertainty after Britain's decision to leave the bloc.