Spain, the current holder of the European Union’s rotating presidency, is in flux following this weekend’s inconclusive election results, so Brussels’ agenda — migration, climate change, and the rest —  will have to wait. 

The current prime minister at Madrid, Pedro Sanchez, assumed the presidency of the European Union on July 1. In Sunday’s election, though, his Socialist party came in second to Alberto Núñez Feijóo’s center-right Popular Party. As yet, no party has the parliamentary majority needed to form a government.

While party leaders are scrambling to lure potential allies, EU priorities are fading from the national agenda. Spain will not be at the table when prominent debates engulf the EU, including regarding relations with Communist China and migration policies, the head of a Brussels-based think tank, Center for European Reform, Camino Mortera-Martinez, tells the Sun. 

“The rotating presidency was a good time for Spain to take center stage,” Ms. Mortera-Martinez says. “We lost it.”

Mr. Núñez Feijóo’s party, known as PP,  won 136 parliamentary seats after the votes were counted Sunday night. It was followed by Mr. Sanchez’s Spanish Socialist Workers Party, which won 122 seats. The right-wing Vox secured 33 seats, less than predicted, followed by the left-wing Sumar, which captured 31 seats. To secure the premiership a candidate’s party must be backed by 176 seats in the 350-seat legislature.

As none of the parties reached such a majority, Congress will reconvene on August 17. King Felipe VI will meet with the leaders and pick the candidate he reckons has the best chances to become prime minister. A debate will take place shortly after that, and a candidate must reach 176 seats in the lower house. If unsuccessful, a second round will take place 48 hours later, where the candidate must reach a simple majority. 

If two months go by from the first vote and no candidate reaches the needed support, the king will dissolve congress and call a new election, to be held around the end of December.

As soon as election results were announced on Sunday, Mr. Núñez Feijóo said he had begun negotiations with other party leaders to gain an absolute majority. “I want to form a government, and I am going to start a dialogue with the rest of the parties,” Mr. Núñez Feijóo tweeted. “I ask all to be responsible, so that Spain does not suffer blockades.”

While the Popular Party is willing to ally with the Socialist Party, Mr. Sanchez seems reluctant to do so. He is already negotiating with the left-wing Sumar and the nationalist separatist groups of the Republican Left of Catalonia and EH Bildu, a political wing of the Basque separatist group ETA. 

“Spain holds the rotating presidency of the Council of the EU, we’re negotiating finance rules in Brussels. We need stability, pro-European sentiments, and centralism,” Mr. Núñez Feijóo told reporters at Santiago de Compostela.“It would be a huge mistake for separatists to govern Spain,” he said, urging the socialist party to coalesce with the Popular Party instead.  

To secure the leadership, Mr. Sanchez would need additional backing from the seven seats of the hard-line separatist party Together for Catalonia, also known as Junts. Its president, Carles Puigdemont, has been in self-imposed exile at Brussels after Spain issued a European arrest warrant against him in 2017 for embezzlement during an independence referendum.

The day after the elections, prosecutors asked a judge to reissue an arrest warrant, following the lifting of his immunity earlier this month. Mr. Puigdemont could face six to 12 years in prison. “One day you are decisive in order to form a Spanish government, the next day Spain orders your arrest,” Mr. Puigdemont tweeted on Monday. 

Mr. Sanchez, at the start of his six-month term as EU president, traveled to Kyiv to underline the bloc’s support for Ukraine’s battle against the Russian invasion. “The war in Ukraine will be one of the great priorities of our presidency, with the focus being on guaranteeing the unity among all member states,” Mr. Sanchez said.

Before the end of the year, Spain aims to finalize a pact on migration, which would decide how the EU processes and relocates migrants. Overseen by Spain, EU ambassadors met this week hoping to reach a final agreement on the immigration reform. Yet, amid disagreements between the Nordic nations and the southern frontline states, they decided on Wednesday to recess for the rest of the summer.

Other items on Brussels’ to-do list this year include reforming the electricity market, imposing regulations over artificial intelligence, forming a strategy to cut down dependence on foreign suppliers, particularly Beijing, and promoting green industries. The bloc also aims to close the long-awaited reform of the European Union’s fiscal rules. 

The EU rotating president sets the agenda, hosts summits, and drives forward meetings and decisions in the 27 member countries. The president’s powers are limited, Ms. Mortera-Martinez says.  Yet, she adds, Spain’s current political limbo is bad news both for the country and for Brussels.

“It is a waste for the European Union to lose a big, important, and pro-EU country at a time where there will be a lot of things to solve,” Ms. Mortera-Martinez says. “I personally worry that we are going to be so disrupted with our domestic problems, that we’re going to go back to the years where we retreated from Europe altogether.”