Argentine demonstrators have staged their biggest-yet show of opposition to Javier Milei’s radical attempt to reshape the South American country with a nationwide strike that shuttered schools and businesses, grounded hundreds of flights, and saw tens of thousands of marchers hit the streets. Milei, a boisterous celebrity economist nicknamed “El Loco” (the Madman), became president in December vowing to free Argentina from decades of “decadence and decline” with his libertarian ideas. Since then, the far-right politician has moved speedily to implement what the former Ukip leader Nigel Farage recently called “Thatcherism on steroids” – first with a far-reaching emergency decree; then with a mega-reform bill known as the “omnibus law”. Together, Milei’s decree and the draft legislation propose hundreds of highly controversial innovations including a wave of privatisations, ferocious spending cuts, a major expansion of presidential powers, and a scaling back of workers’ rights and the right to protest. Nine of 18 government ministries have been closed, including those responsible for education, the environment and women, gender and diversity. Argentina’s currency, the peso, was devalued by more than 50% against the dollar. Milei claims such moves will rescue Argentina from the “economic hell” he blames on his Peronist predecessors. But the agony has intensified since his inauguration. Monthly inflation hit 25.5% last month compared to 12.8% in November. Annual inflation has reached a three-decade high of 211.4% – even higher than in Venezuela, a country reeling from a decade-long economic collapse. On Wednesday lunchtime thousands of objectors marched through the capital, Buenos Aires, and other major cities, to voice their anger at Milei’s moves. “We’re fighting against the way in which the far right is basically trying to eliminate our rights of existence on all levels, from healthcare to work,” said Federica Baeza, an LGBTIQ+ activist and art curator who was among the crowd outside congress as the 12-hour strike began. “What the ultra-right does not understand is that we live in an unequal world and that the state has to be active in order to reverse this situation,” added Baeza, 45. Another marcher, Ivana Uez, had brought her daughter hoping to stop Milei stripping away her five-year-old’s rights. “It’s not just about posting images and comments on Instagram or Twitter. You have to come, you have to show up, you have to meet with others [and] see what other realities there are,” said Uez, 38, fretting that Milei’s “catastrophic” deregulation of the housing market would send rents soaring. Nearby, an elderly man held a placard reading: “I’m retired. I earn 106,000 pesos [about $84 a month]. I’m starving to death. Milei [you’re a] son of a bitch.” The union leader Hugo Yasky told local radio the strike was against the “utter social insensitivity” of a government which has slashed energy and transport subsidies. Benjamin Gedan, the director of the Wilson Center’s Latin America Program, called the walkout an early “shot across the bow” of Milei’s administration and wagered it would be the first of many such mobilizations. “This could be the beginning of a very tumultuous period in Argentina as the government charges ahead with a radical reform program,” Gedan predicted. “The [economic] pain we have seen is extraordinary … prices are increasing at a head-spinningly fast rate. That’s real pain with real social and political consequences.” Lara Goyburu, a political scientist from the Red de Politólogas network, predicted March and April could prove “very turbulent months” as the cost of utility bills, private health insurance and education rose and children returned to school, putting more pressure on families. Milei’s ministers voiced defiance as workers downed tools at the request of Argentina’s biggest trade union, the General Confederation of Labor. “[The strike] confirms we’re on the right path,” tweeted the foreign minister, Diana Mondino, claiming it had been organized by millionaire oligarchs “with bullet-proof cars and chauffeurs”. Milei’s hard-line security minister, Patricia Bullrich, blamed the walkout on “mafioso unionists”. “No strike will stop us,” vowed Bullrich, who had threatened to dock the wages of public sector workers who took part. Beyond his bid to transform Argentina, Milei has spent recent weeks nurturing his image as a darling for the global populist right, with considerable success. During a viral speech at the World Economic Forum in Davos, Milei slammed the “noxious ideas” of “neo-Marxists” who pushed the “bloodthirsty abortion agenda”. Elon Musk tweeted a salacious photomontage indicating his approval while the former US president, Donald Trump, claimed Milei was making progress in “making Argentina great again” despite inheriting “a total mess”. Speaking to the conservative news outlet Voz Media, Farage compared Milei’s “exciting” plans to Margaret Thatcher’s attempt to resuscitate the British economy during the 1980s. “Britain was in a state of terrible decline. The trade unions running the country, high inflation, high unemployment, low growth. We had become the sick man of Europe,” Farage claimed, hailing the “extraordinary gains” Thatcher’s “very painful medicine” had brought about. Milei was now doing precisely the same, Farage believed. “But he’s doing it on a scale that is almost beyond anyone’s thinking … This is Thatcherism on steroids.” Polls suggest a majority of Argentinians still support Milei’s administration. But as he addressed thousands of demonstrators outside congress on Wednesday afternoon, Pablo Moyano, the general secretary of Argentina’s truck drivers’ union, claimed many were waking up. “This is historic. It’s an enormous mobilization just 45 days after the new government took over,” Moyano said. “Already, people are making themselves heard.”