MADRID — The Spanish government teetered on the brink of collapse Wednesday, as the dispute over the status of the prosperous northeastern region of Catalonia stymied passage of a national budget and threatened to usher in another round of protracted political uncertainty.
Prime Minister Pedro Sánchez, one of the few Socialist leaders left standing on the European political stage, was hoping to use Spain’s recent economic recovery to raise social spending as part of his budget, in an effort to address the inequalities that have accompanied Spain’s economic recovery.
Instead, Mr. Sánchez, who leads a precarious minority government, was now facing a decision in coming days on whether to call new elections — a seeming inevitability — after Catalan lawmakers withdrew their support, trying to force the issue of independence for their region back to the fore of Spanish politics.
For Spain, and indeed all of Europe, a new round of political turbulence could hardly come at a worse time. The Continent already faces the challenge of Brexit, as the British divorce from the European Union is called, with a deadline of March 29 looming.
Elsewhere, from Eastern and Central Europe to Italy to the hinterlands of France, populist forces continue to test the very cohesion of the bloc, both on the streets and in the halls of power.
Spain, by comparison, was shaping up as a relative bright spot. But a return to elections would most likely reveal a fractious and increasingly polarized political landscape that makes Spain less the exception than the rule in Europe today.
Spain stood out as “a rare beacon for Social Democrats across Europe,” as well as one of the few large members of the European Union led by a government committed to more European integration “in the midst of Brexit and fracture in Italy,” said Pablo Simón, a politics professor at the Carlos III University in Madrid.
“We’re now seeing that Spain, on top of the issue of Catalonia, is not different and has just the same problems as the countries around us, in terms of fragmentation and parties that struggle to maintain credibility and form solid alliances.”
Given the growing polarization in Spain, Professor Simón added, a snap election could produce “all sorts of scenarios, including a new period of complete blockage.”
Indeed, Mr. Sánchez and his Socialist party came to power only by a thread in 2018, two years after the country held two inconclusive national elections and political parties haggled for nearly a year over who should run the government.
In the end, Mr. Sánchez formed unwieldy alliances, including with Basque and Catalan nationalist parties, to oust Mariano Rajoy, the conservative prime minister, in a parliamentary vote of no-confidence and form his own Socialist government with only about a quarter of the seats in Parliament.
That vulnerability, ever-present since Mr. Sánchez took office last June, finally manifested itself in his budget vote.
On Wednesday, lawmakers turned down the government’s budget plan by a vote of 191 to 158, with one abstention. It was the first time since 1995 that the Spanish Parliament had rejected a government’s budget.
Mr. Sánchez left Parliament without taking questions, but his budget minister later acknowledged that the government considered its mandate to be contingent on having a budget for 2019.
Under Spanish law, the next national election was to be held by mid-2020 in any case. But it seems almost certain that voters will instead return to the polls before the summer.
This time around, as Spain has shifted from a two-party system to a much more fragmented political landscape, a national election could be even more unsettling and unpredictable.
Recent opinion polls suggest that opposition conservative parties could win enough votes to form a right-wing coalition government. At the same time, a far-right party, Vox, has emerged on the political stage for the first time since the end of the Franco dictatorship in the 1970s.
In December, Vox achieved its electoral breakthrough in an election in Andalusia, the southern region of Spain, in part on concerns over a recent rise in number of migrants coming from Africa.
New elections would be a test of Vox’s viability, and potential role as a kingmaker, at the national level. The party also wants to recentralize Spain and has a front-line role in the landmark trial of 12 former Catalan leaders before the Supreme Court in Madrid, which started on Tuesday. Alongside state prosecutors, Vox’s lawyers filed their own set of charges against the Catalans, who are accused of rebellion and sedition in connection with the 2017 referendum and the region’s subsequent declaration of independence.
Mr. Sánchez’s own prospects are unclear, but in the past he has demonstrated sharp survival skills. In 2017, he was ousted as leader of his party, but just a year later, he had not only retaken the helm of his party but also become prime minister.
The debate over Mr. Sánchez’s defeat on Wednesday focused less on his spending plans than on his handling of Catalonia — highlighting the power that Catalonia’s territorial conflict has to shape national politics.
Catalan lawmakers turned their backs on Mr. Sánchez after failing to persuade him to consider holding a second independence referendum, after the region held one in October 2017 that was ruled unconstitutional and that Spanish police sought to block.
Upon taking office, Mr. Sánchez pledged to renew dialogue with the governing pro-independence politicians in Catalonia, in an effort to end a crisis that reached boiling point in 2017. He soon met with Quim Torra, the separatist leader of Catalonia, who also took office in June.
But their talks got nowhere, and Mr. Torra recently warned that his party would not approve a new Spanish budget unless Mr. Sánchez considered holding another referendum, this time with the agreement of the central government in Madrid.
Mr. Sánchez’s government rejected this proposal as political blackmail, insisting that such a referendum was incompatible with the Spanish Constitution.
For even opening the dialogue, some right-wing politicians labeled Mr. Sánchez as a traitor to Spanish unity. At their urging, tens of thousands of people demonstrated in Madrid last weekend, demanding a new election and denouncing the prime minister’s handling of Catalonia.
After the budget vote, Pablo Casado, who replaced Mr. Rajoy as leader of the opposition Popular Party, told a news conference that an election was unavoidable, calling the budget setback “a vote of no-confidence against Mr. Sánchez.”
In recent months, Mr. Casado has called for a return to direct rule from Madrid over Catalonia in order to end the secessionist challenge.
“The Socialists have said they would keep the door open to talk with those who staged a coup d’état” in 2017, Mr. Casado said on Wednesday. “We want a government that depends neither on separatists nor on populists.”
Albert Rivera, the leader of the Ciudadanos party, also accused Mr. Sánchez of joining forces with “those who want to liquidate Spain.”
He told a separate news conference: “There are two problems in Spain: separatism and having Sánchez in the Moncloa,” the government compound in Madrid.
Joan Tardà, a Catalan lawmaker, said his separatist party had rejected a budget that included higher spending in Catalonia because Mr. Sánchez was “running scared” from Spain’s right-wing opposition and refusing an open negotiation with the Catalan independence movement.
“It is a huge lost opportunity because they know that, sooner or later, they will have to negotiate a democratic solution,” he told reporters.