MADRID — Spain’s governing Socialists, who won an election in April but without a parliamentary majority, threatened on Monday to call a fresh ballot if opposition parties persist in blocking acting Prime Minister Pedro Sanchez’s attempts to form a minority government.

This was the only alternative if Sanchez could not win the support of parliament, Jose Luis Abalos, a high-ranking Socialist, told reporters.

Sanchez, invited last week by King Felipe VI to seek parliamentary approval to be sworn in as prime minister, began meeting this week with the leaders of opposition parties.

In a first round of voting in parliament, Sanchez needs support from a majority of lawmakers to win approval. With the support of far-left Podemos and some smaller parties, he could be voted in in a second round vote, which requires only more votes in favor than against.

The right-wing People’s Party (PP) and center-right Ciudadanos have both said they will seek to block Sanchez’s swearing-in, while Podemos has conditioned its support on a place within Sanchez’s government, something the Socialists have ruled out.

"If not only Ciudadanos and the PP but also Podemos are obstructive, we will need to see what the options are because clearly this can either work or not,” Abalos said.

Earlier on Monday, Podemos leader Pablo Iglesias, speaking in a television interview, said the leftist party would seek to control ministries involved with social policy. — Reuters