Argentina’s largest labor unions have called a one-day nationwide strike to protest President Javier Milei’s flagship overhaul of the country's labor law as the bill faces an uncertain passage through the lower house of Congress. Milei’s government considers the reform of Argentina’s half-century-old labor laws crucial to its efforts to lure foreign investment, increase productivity and boost formal hiring in a country where about two in five workers are employed off the books. It’s the first big test of his political strength since his libertarian party won midterm elections last year. The unions organizing Thursday's strike argue the law will weaken long-standing protections for workers.