Spain's Socialist party rejected a re-worked offer on Tuesday to form a coalition government with the far-left Unidas Podemos that could have mapped a way out of a four-month political hiatus that began with an inconclusive national election.
Socialist leader and caretaker prime minister Pedro Sanchez has been trying to rally support among parliamentarians to confirm him as premier since April, when voters gave his party more support than any other, but not enough to command a majority.
Podemos repeated on Tuesday an offer to form a coalition, on condition it could name one deputy prime minister and three cabinet ministers.
"The Socialist party considers (this) coalition unworkable," it said in a statement, suggesting Podemos and its allies try to find another way to support a new administration.
The statement said the party agreed with a lot of the programs Podemos put forward on Tuesday, which include a further hike to the recently-raised minimum wage and more ambitious targets for renewable energy generation.
But two failed attempts to form a government in July showed that they could not govern in coalition, the Socialists said.
Even if they reconciled their differences, the Socialists and Podemos would need the cooperation of other parties to govern.
Sanchez has failed twice to persuade to back him with their votes, and now has until late September to avoid another election.
After losing the second vote, he blamed Podemos leader Pablo Iglesias for making unacceptable demands.
Iglesias had relinquished a demand to hold a cabinet post himself, ceding to objections from Sanchez, who cited differences between the two including on how to deal with a secession bid in the region of Catalonia.