Four million people in Spain have joined a general strike.
They are protesting rising rents and evictions in the middle of a housing crisis.
An election is set to be held on November 29.
Four million Spanish workers took part in a general strike on Wednesday, unions said, enduring stormy weather to set up picket lines in a protest against the country's housing affordability crisis less than three weeks before a snap general election.
It is the first general strike since workers downed tools in 2012 against austerity measures during the euro zone debt crisis. The walkout is backed by Spain's two largest unions, UGT and CCOO, representing more than a million workers, as well as tenants' associations angry about rising rents and evictions.
Prime Minister Pedro Sanchez hopes to harness voter resentment over housing in the November 29 election to shift the political narrative away from corruption cases involving his inner circle and a deadly train crash last month. So far, his Socialist Party still trails in opinion polls.
Police say they arrested 40 people through the morning as protesters took to the streets. ( Reuters: Susana Vera )
The strike follows weeks of demonstrations provoked by the eviction and subsequent death of an 87-year-old woman in Madrid.
Those protests, along with parliament's rejection last month of government decrees aimed at curbing evictions and limiting rent pressures, prompted Mr Sanchez to call the snap election.
On Madrid's Gran Via, one of the capital's main shopping streets, protesters cheered as stores including Primark, H&M and Pull & Bear drew their shutters amid a heavy riot police presence.
Spain has a deficit of about 750,000 homes, which is set to grow to more than a million by 2028, according to the central bank.
Workers who are joining the 24-hour general strike are demanding wages that allow access to decent housing. ( Reuters: Albert Gea )
With fewer people able to afford a home, renting has increased sharply, putting pressure on that market.
The average rental price of €1,176 ($1,904) is equivalent to about 98.7 per cent of a young person's average monthly salary in Spain, according to the Youth Council of Spain.
"I'm 36 years old and I still can't move out on my own," said Madrid resident Jesus Gonzalez, who works in a hospital IT department and supports the strike. "Rents just keep going up, house prices just keep going up, and it's simply impossible."
Protests are taking place across the country in the lead up to a general election. ( Reuters: Alejandro Martinez Velez )
Angela de Miguel, vice president of Spain's main business lobby CEOE, said the strike was counterproductive because small businesses were also affected by the housing crisis, since shortages of homes made recruitment more challenging.
The tenants' union said it still expected participation in the strike to reach five million of Spain's 23 million workers by the end of the day.
According to UGT and CCOO, 90 per cent of workers participated in the strike in the automotive sector.
Electricity demand dropped by as much as 15.5 per cent between 10am and 11am., according to Spain's grid operator Red Electrica.
With fears of clashes, many shops across Spain are taking pre-emptive measures. ( Reuters: Vincent West )
Barcelona's metro said no trains would run outside peak commuting hours, while Madrid's metro said peak-hour usage was down 42 per cent compared to the same period last week.
However, with more people able to work remotely and the increasing weight of services in Spain's economy, the impact of the strike is likely to be less pronounced than in previous years, according to Miguel Cardoso, chief economist at BBVA Research.
He estimated that the strike could shave 0.1-0.2 per cent off Spain's annual gross domestic product.
Spain's fast-growing hospitality and finance industries are less unionised than the public and industrial sectors.
Police had reported 40 arrests by midday from 476 incidents linked to the general strike, including blockades of offices and industrial estates and burning of rubbish containers.
Unions said they would file a criminal complaint against what they described as a "disproportionate" response during a police operation involving tear gas and batons that left 20 protesters injured.
