(Bloomberg) -- El Salvador’s President Nayib Bukele claimed victory for his allies in legislative elections on Sunday, as the nation waits for official results to be published.With just 0.2% of ballot sheets tallied four hours after polls closed, Bukele’s Nuevas Ideas party led with 63%, according to official TV. The Gana party, which is allied to the president, had 6%, while the Arena and FMLN, which dominated the country for decades, had 26% between them.Bukele published a tweet saying “victory” with images of fireworks exploding.A big win for Bukele would concentrate power in the 39-year-old leader, making it easier for him to advance his agenda, issue debt, and reach a deal with the International Monetary Fund. It would also alarm critics, including some U.S. lawmakers, who say the Central American nation is sliding toward authoritarianism.Since his election in 2019, Bukele has repeatedly clashed with the legislature, which until now has been controlled by his opponents, and last year even sent troops into the building.Investors are betting that with a strong result, the government will seek a deal with the IMF. That would likely include fiscal austerity to reign in a deficit that widened to more than 8% of GDP last year. Such a program would require approval from two-thirds of congress.A big victory could also set the stage for constitutional changes, a worrisome development for critics who see Bukele amassing excessive power.Why El Salvador Vote Is and Isn’t About Its President: QuickTakeVice President Felix Ulloa has said he hopes to present constitutional reforms to congress later this year, which may include changes to presidential term limits. Under current law, reforms would require approval by two consecutive legislatures, meaning not until 2024.Bukele’s attacks on corruption, and the conservative Arena party and the leftist FMLN, who between them have dominated El Salvador for decades, have helped keep his approval rating around 90% since taking office. His government also boasted about its harsh treatment of jailed gang members, winning approval of some people in one of the world’s most crime-ridden countries. For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2021 Bloomberg L.P.