Legislators in Mexico’s lower house of Congress on Wednesday morning approved a sweeping proposal to redesign the entire judiciary, the first step toward shifting the country to a system in which nearly every judge is elected to office.

The vote advances one of the most far-reaching judicial overhauls in any major democracy in recent decades, raising tensions in Mexico over whether the measures will improve the functioning of the country’s courts or politicize the judiciary in favor of the ruling Morena party and its allies. In the current system, judges are appointed based on special training and qualifications.

The lower house will now have to iron out more than 600 details of the bill before it moves to the Senate, where the ruling bloc is just one seat short of a supermajority — though the measure is expected to pass.

On Tuesday, when lawmakers met to discuss the initiative, eight of the 11 Supreme Court justices voted to suspend sessions for the rest of the week in support of striking judicial employees at the high court, who began a walkout earlier in the week — joining the hundreds of judicial workers and federal judges across Mexico who went on indefinite strike last month over the proposed changes.

In the hope of delaying the vote, striking workers formed a human chain to block access to Mexico’s lower house. But legislators switched venues to a sports complex and proceeded with the debate, which often turned into a tense exchange of accusations.

After an hourslong session that dragged on well into Wednesday morning, 359 lawmakers present voted in favor of the overhaul. Only 135 opposed it.