PARIS — Hundreds of thousands of workers, students and pensioners flooded the boulevards of European capitals on Friday in the largest May Day mobilizations in nearly a decade, with traditional labor demands sharing the streets alongside anger over the economic toll of the Iran war and growing unease about an accelerating wave of artificial-intelligence-driven job losses in white-collar sectors.

French police placed turnout in Paris at 142,000 by mid-afternoon, while the CGT union federation claimed more than 300,000 marchers on a route that stretched from Place de la Republique to Place de la Nation. Smaller but substantial demonstrations filled Berlin’s Frankfurter Tor, Rome’s Piazza San Giovanni, Madrid’s Puerta del Sol and the long avenue leading to Athens’ Syntagma Square. Organizers in Brussels said roughly 28,000 marched past EU institutions, an unusually large showing for a city where May Day rallies typically draw under 10,000.

“The war is over and the bill has arrived,” said Sophie Binet, the secretary-general of the CGT, addressing a forest of flags at Place de la Nation. “For six weeks our governments told us the priority was Hormuz. Today we are telling them the priority is our pay slips, our pensions, and the jobs the algorithms are quietly deleting while no one is looking.”

The mood across the continent was distinctly more political than recent May Day editions, which had been dominated by narrower disputes over retirement ages and public-sector wages. Union leaders in five capitals framed Friday’s rallies as a referendum on the post-war agenda, calling for windfall taxes on energy majors, expanded purchasing-power supports for households squeezed by a year of elevated inflation, and what an Italian CGIL banner in Rome described as “a human firewall against the AI rollout.”

Inflation in the euro area peaked at 4.6 percent in March, driven largely by the Brent crude spike that briefly pushed pump prices above 2.30 euros per liter in France and 2.10 euros in Germany. The Iran-Israel ceasefire that took effect April 15 has eased the energy shock — Brent settled near $93 a barrel on Thursday — but headline disinflation has lagged household perceptions, and core services prices remain sticky. The European Central Bank, which held rates steady at its April 24 meeting, has signaled it is in no hurry to ease, frustrating unions that had hoped for visible relief by summer.

“Wages are running behind prices for the fifth consecutive quarter, and the cumulative real-income loss for a median French household is now north of 2,200 euros since the start of 2024,” said Mathilde Roux, a labor economist at the OFCE in Paris. “The energy shock from the Iran war is a smaller line item than the public assumes, but psychologically it has become the symbol of a decade of erosion. That is what filled the streets today.”

The AI thread running through Friday’s marches reflected a sharper turn in European public opinion since the U.S. House Ways and Means Committee killed the Sanders-Ocasio-Cortez moratorium bill on April 22. Several large German employers announced restructurings in March and April that explicitly cited generative AI tools as the reason for cuts in middle management and customer-service roles, and a Eurobarometer survey released this week found that 61 percent of respondents in the EU now expect AI to “significantly reduce” employment in their own field within five years, up from 44 percent last autumn.

In Berlin, IG Metall and the white-collar union ver.di for the first time staged a joint May Day march under a single banner reading “Mitbestimmen, nicht ersetzt werden” — “Co-decide, not be replaced.” Ver.di chair Frank Werneke told a crowd at the Brandenburg Gate that the union was preparing a framework demand for what he called “algorithmic co-determination,” a right for works councils to review the deployment of generative AI systems before they take live decisions affecting staffing. German Labor Minister Hubertus Heil, addressing a separate union event in Hannover, said the government would publish a white paper on AI in the workplace in June and called Werneke’s proposal “a serious idea that deserves a serious hearing.”

Italian Prime Minister Giorgia Meloni used a televised address Friday morning to defend her coalition’s record on purchasing power and to push back against opposition claims that war-related spending had crowded out wage support. “Italy will not borrow from its grandchildren to subsidize protests against arithmetic,” Meloni said, drawing a sharp rebuke from CGIL leader Maurizio Landini, who told the Rome rally the prime minister had “confused arithmetic with austerity for the last time.”

In Asia, May Day demonstrations were generally smaller but threaded similar themes. Roughly 18,000 South Korean workers marched in Seoul’s Gwanghwamun Square under the banner of the Korean Confederation of Trade Unions, focused on shipyard wages and a controversial Yongsan-district redevelopment plan, with smaller contingents calling attention to layoffs at semiconductor packaging suppliers that had been promised AI-era expansion. In Tokyo, the Japanese Trade Union Confederation, Rengo, held its annual Yoyogi Park rally and used the occasion to press Prime Minister Sanae Takaichi’s government on a stalled overtime-reform bill. A modest demonstration in Hong Kong, the first authorized May Day march in three years, drew about 2,200 participants under tight police supervision.

The Philippines saw its largest May Day mobilization since 2019, with an estimated 35,000 workers marching from Mendiola Bridge to Liwasang Bonifacio in Manila, focused on remittance-worker protections in the wake of the Gulf evacuations. Roughly 47,000 Filipino workers were repatriated from Saudi Arabia, the UAE and Iraq during the Iran war, and many returned to find their domestic placement contracts in dispute. “Our compatriots came home to nothing,” said Elmer Labog, the chairperson of Kilusang Mayo Uno. “The government cannot tell them to wait. They are already waiting.”

Friday’s rallies were largely peaceful, though French police reported 38 arrests in Paris after a “black bloc” group broke off from the main CGT cortege and smashed shop windows along Boulevard Voltaire. Interior Minister Bruno Retailleau condemned the violence in a late-afternoon statement and praised what he called “the responsible majority of marchers.”

In Brussels, European Commission Vice President Roxana Minzatu, who holds the social-rights portfolio, said the Commission would bring forward proposals for a strengthened “right to disconnect” directive and a separate framework on AI workplace transparency before the August recess. She said additional steps on energy-bill relief and a long-delayed minimum-wage review would be discussed at the EU social summit scheduled for Porto in late June.