Spaniards were voting Sunday in local and regional polls seen as a barometer for a year-end general election which surveys suggest Prime Minister Pedro Sanchez will lose, heralding a return of the right.
The stakes are high for Sanchez, whose Socialist party governs the eurozone's fourth-largest economy in coalition with the far-left Podemos.
Voters are casting ballots for mayors in 8,131 municipalities while also electing leaders and assemblies in 12 of Spain's 17 regions – 10 of which are currently run by the Socialists.
In an update at 2:00 pm (1200 GMT), five hours into voting, participation in the local elections stood at 36.54%, or 1.59 percentage points higher than in the 2019 polls, official figures showed.
Some 35.5 million people are voting in the local elections while 18.3 million are eligible to cast ballots in the regional polls.
Balloting ends at 8.00 p.m., with initial results due out two hours later.
Sanchez has been in office since 2018, and Sunday's elections find him facing several obstacles: voter fatigue with his left-wing government, soaring inflation and falling purchasing power.
"I do think it's an important test (ahead of the year-end elections). It's the only way we have of expressing our opinion about all these years they've been in government," 61-year-old doctor Maria Alonso told AFPTV after voting in Madrid, without saying who earnt her vote.
Microbiologist Irene Diaz said the local and regional polls "were as important" as the upcoming general election.
"At the end of the day, these are elections in your city which involve laws and legislation that will end up impacting your day-to-day life," the 30-year-old said.
Sanchez expressed confidence that voters would cast their ballots responsibly.
"Most of our citizens will vote positively... for what is important: for public healthcare, public education and housing policies for our young people," he said after voting in Madrid.
Opposition leader Alberto Nunez Feijoo, head of the right-wing Popular Party (PP), urged people "to vote massively" and ensure the next government was a strong one.
"We have difficult years ahead of us but... the stronger the government, the stronger our democracy will be and the faster we will get out of the economic, institutional and social problems we have in our country," he said.