Conservative Spanish Prime Minister Mariano Rajoy surrendered to the math on Saturday and abandoned his latest attempts to form a new government following last month's parliamentary elections.
But he warned that the Socialists would be embarrassed by the far-left Podemos group, which would be a junior member in a Socialist-led government.
"The government that [Socialist leader] Pedro Sanchez is desperately seeking would be beholden to Podemos and humiliated by them," said Rajoy, who abandoned his own attempts to head a new cabinet.
Accusations of blackmail
Indeed, hours later the Socialists accused Podemos of "blackmail." They said they would "not enter into negotiations with other political forces to try to find alternatives to a stable government, especially when they are proposed through blackmail and by giving partisan interests priority over the citizens'."
In thinly veiled criticism of Podemos, the Socialists said that "in order to build a new national project," talks on "policies and specific ideas" must be held - not on "tactics, partisan interests or unilaterally imposed (decisions)."
The Socialists added that they would continue to talk to all parties to "evaluate the situation."
Podemos leader Pablo Iglesias suggested that he could be a deputy prime minister in a Socialist-led government.
"We have decided to seize the initiative and take a step forward," Iglesias told reporters after meeting the king. "There is no more time for hesitation. Either you're for change or for stagnation and impasse."
Rajoy's Popular Party won last month's parliamentary election but secured only 123 mandates in the 350-seat parliament. Rajoy wants to form a grand coalition with the Socialists (89 seats) and Cuidadanos (40 seats), which would create a solid majority in parliament.
But Socialist leader Sanchez has other ideas: He wants to form an alliance of "progressive forces" that would include Podemos' 65 seats and the two seats of the United Left. Such a coalition would also need the support of tiny Basque and Catalan nationalist parties to survive a confidence vote if they lost the backing of Ciudadanos.
Spain's political landscape has been gridlocked since last month's parliamentary election saw Podemos and Ciudadanos enter parliament for the first time, fracturing the country's political landscape and making a coalition much more difficult.
The parties have two months from the December 20 election to form a new government. A failure to do so would result in a new snap election.
The Socialists and Podemos seem keen to form a coalition, but Sanchez warned that the two sides had to first agree on a governing program.
bik/rc (AFP, Reuters, AP)