Argentine President Javier Milei's libertarian La Libertad Avanza party achieved a significant electoral breakthrough on May 18, securing first place in Buenos Aires City Legislature elections with 30.13% of the vote, according to La Nacion. Presidential Spokesperson Manuel Adorni, Milei's hand-picked candidate, led the ruling party to victory with a nearly three-point margin over Peronist leader Leandro Santoro's Es Ahora Buenos Aires, which garnered 27.35%.

The results delivered a devastating blow to the centre-right PRO party, which has governed Buenos Aires City since 2007 and considers the capital its stronghold. The PRO until recently largely supported Milei in Congress but is now challenging him for control of the centre-right political movement. Its candidate Silvia Lospennato underperformed, managing just 15.92% and relegating the party to a distant third place.

"Today, the yellow bastion was painted purple – and from now on, we're going to paint the whole country purple!" Milei declared, as cited by Perfil, referencing the colour shift from PRO's yellow to his party's purple branding.

"Today, we choose between two models. Between the model of the caste, of privileges, that of a few; and the model of freedom," Adorni stated in his victory speech. He extended an invitation to dissatisfied politicians to join Milei's movement – an overture that may now appeal to PRO members.

“What this election yielded is that society understands we're the best way to end Kirchnerism for good, which was nothing but a tragedy for Argentina,” he added, taking a swipe at the leftist Peronist political movement of former President Cristina Fernández de Kirchner.

The election results will grant La Libertad Avanza 11 of the 30 contested seats, making it the second-largest force in the City Legislature with 14 lawmakers, behind only the united Peronist caucus with 20.

Voter turnout reached just 56%, AFP reported, the lowest in a local election since 1997, despite favourable weather and the introduction of the new BUE electronic ballot system. This marks a significant drop from the 76.7% turnout in the 2023 general election.

Political analyst Mariel Fornoni told Reuters that the "Milei's administration had sought to frame Sunday's local election as a referendum on his government's national economic achievements, touting his success in bringing down inflation and securing the country's first budget surplus in 14 years last year."

This victory in Argentina's capital represents a crucial political win for Milei's libertarian movement ahead of October's national midterm elections, potentially strengthening his hand as he pursues bold economic reforms that have faced significant resistance from opposition parties and labour unions but have earned praise from multilateral financial institutions such as the IMF and the World Bank.