Argentina’s Senate narrowly passed President Javier Milei’s sweeping economic reform bill, delivering a tentative legislative victory to the right-wing leader even as protesters clashed with riot police.

Lawmakers in Argentina’s upper house on Wednesday voted 37 to 36 to approve the bill after a marathon debate, with Vice President and head of the Senate Victoria Villarruel casting the deciding vote in favor of Milei’s economic measures.

The bill, which was initially backed by the lower house in April, will now be studied point by point before it is expected to be fully approved on Thursday.

The reform bill is a core tenet of Milei’s push to revive the country’s crisis-stricken economy. Among other issues, the bill seeks to privatize some of the country’s state entities, provide a generous incentive scheme for foreign investors and water down labor rights.

Photos published on Getty images showed anti-riot police officers deployed water cannons to disperse protesters and a car had been set ablaze during the demonstrations.

The Buenos Aires Times reported that, while many of the protesters demonstrated peacefully, anti-riot police used tear gas, and at least 18 people were arrested.

“Today there are two Argentinas,” Argentina’s vice president said, according to Reuters.

“A violent Argentina that sets a car on fire, throws rocks and debates the exercise of democracy, and another Argentina with workers waiting with great pain and sacrifice for the change that they voted for,” Villarruel said.

Leftist political parties and labor unions are bitterly opposed to Milei’s economic agenda.

In early May, Milei’s government faced its second general strike in less than six months, with workers nationwide angered by the proposed austerity measures and by a profound economic crisis.

The libertarian leader, who won a presidential runoff vote late last year, has said there is no alternative to his so-called “shock therapy” to remedy the situation.