Spain's first general strike in 14 years, held Wednesday over the housing crisis, ended with clashes in Barcelona and Madrid.

After a peaceful march in Barcelona, protesters smashed storefronts on Paseo de Gracia, set small bonfires, burned dumpsters, and launched fireworks at police in riot gear; a hooded group attempted to break into an Apple store.

The AP also reported marches of 400,000 people in Barcelona by activists' count, and 120,000 in Madrid despite pouring rain, per government officials.

The walkout landed less than three weeks before Spain's November 29 snap election, which Prime Minister Pedro Sánchez called after weeks of protests over the eviction and death of 87-year-old tenant Maricarmen.

Sánchez's government made the unusual move of backing the strike, and Time reports the administration appears hopeful it will be buoyed by resentment over the opposition's block on new housing measures.

Opposition leaders pushed back hard: Popular Party spokesman Miguel Tellado called the strike a 'gift by the unions to their political parties,' while Vox chief Santiago Abascal labeled it a 'campaign for Sánchez' according to Time. Polls published November 9 show Sánchez's party trailing.

Union organizers CCOO and UGT reported work stoppages of 90% in the automotive and port sectors, 85% in the meat industry, 82% in waste collection, and 75% in energy, with total halts at Volkswagen's Navarre plant and SEAT's Martorell factory.

CCOO chief Unai Sordo said the strike 'exceeded the labor unions' expectations,' and the tenants' union estimated four million participants — around 17% of Spain's workforce — possibly growing to five million by day's end, according to Time.

Employers' group CEOE countered that only 5% of workers joined, calling the action a 'failure,' a dispute over participation both AP and Time attribute to their respective sides. Madrid metro peak usage fell 42%, per CNN.

The strike was the first in Spain whose main push grew from housing unrest, under the slogan 'Salaries. Housing.

Prices.' Spain has a shortfall of roughly 750,000 homes that the central bank projects will exceed one million by 2028, and Time reports rents rose 87% between 2015 and 2025 while wages grew about 30%.

The Youth Council of Spain calculates average monthly rent of €1,176 ($1,315) equals nearly 99% of the average salary for workers aged 16 to 29, and the average age for leaving the family home now stands at 30.2 years.

Activists are demanding automatic lease renewals; unions want more public housing and a new minimum wage agreement.

The disruption hit a eurozone economy of roughly 23 million workers: Barcelona's metro and buses stopped outside rush hours, schools and universities closed, and about 5% of Wednesday's flights were canceled according to airport operator AENA.

Time reports officials counted at least 1,044 incidents, and CCOO Madrid said it planned to file a criminal complaint over a 'disproportionate' police response involving batons and pepper spray that allegedly injured 20 protesters.

CNN cites BBVA Research economist Miguel Cardoso estimating the strike could shave 0.1% to 0.2% off annual GDP, a modest economic cost but a charged political one ahead of a vote where housing has become a defining issue.

Attention now shifts to Madrid's parliament: Congress's Permanent Deputation is due to vote Thursday on revised versions of the housing decrees that opposition lawmakers rejected in early October, legislation intended to strengthen tenants' rights and curb rent costs, according to Time.

Time also reports analyst Oriol Bartomeus said the Socialists need the strike to succeed without violence so the campaign can swing back to housing.

Sánchez kept a low profile on strike day, posting earlier about past social wins like the 40-hour week, while PP leader Alberto Núñez Feijóo warned unions they would 'tie your image to Pedro Sánchez forever' if they backed the action, per Time. The snap election follows on November 29.