MANILA, Philippines — A leadership standoff in the Philippine Senate ended Wednesday with the removal of an ally of former President Rodrigo Duterte as leader of the chamber, which will soon start the impeachment trial of his daughter, incumbent Vice President Sara Duterte.

With 13 of 24 senators backing him, Sherwin Gatchalian, an ally of President Ferdinand Marcos Jr., was elected Senate president. His rival, Alan Peter Cayetano, a key supporter of Duterte, conceded defeat.

Both had claimed leadership of the Senate in the last two weeks based on contrasting legal interpretations of the quorum that led to their elections. An allied senator of Cayetano, however, defected Wednesday and gave his rivals’ bloc a clear majority.

“It’s a relief,” Jean Franco, a political professor at the state-run University of the Philippines said, but added that the country’s democracy, “with its weak and fragile institutions,” faces more headwinds.

The Senate infighting has been perceived as being swayed by the long-running political disputes between Marcos and Vice President Duterte. The country’s top two leaders were once allies but had a bitter falling out in a high-profile dispute that reflects the divisions and turbulent politics long plaguing the Asian democracy.

The vice president has blamed Marcos for the arrest of her father, Rodrigo Duterte, and his handover to the International Criminal Court in The Hague last year. The detained former president is scheduled to be tried by the global court starting in November for alleged crimes against humanity.

The charges stem from his brutal anti-drugs crackdowns, which left thousands of mostly poor suspects dead while he was in office. He has denied authorizing extra-judicial killings.

Cayetano captured the Senate presidency on May 11 after his Senate faction attained a slim majority when Sen. Ronald dela Rosa suddenly reappeared to support him after months of hiding.

Dela Rosa once served as Rodrigo Duterte’s national police chief and has been named by the ICC as a co-perpetrator of the former president in the widespread killings of drug suspects. After the ICC unsealed a warrant for dela Rosa’s arrest on May 11, he went back into hiding and remains at large.

Another Cayetano ally, Sen. Jinggoy Estrada, was arrested and jailed on June 1 after being indicted on a plunder charge. He was accused of receiving huge kickbacks from a flood control project, a charge that he denies.

Control over the Senate is crucial. It’s expected to start the trial in July of the vice president, who was impeached by the House of Representatives last month over criminal charges, including unexplained wealth and publicly threatening to have Marcos assassinated.

The House is dominated by Marcos’ allies. The vice president denies the allegations, which her supporters say were fabricated to prevent her from pursuing an announced plan to seek the presidency when Marcos’ six-year term ends in 2028.