Allies of Philippine President Ferdinand Marcos Jr looked set to win at least half of the available Senate seats in a midterm election on Monday, an unofficial tally showed, in a contest seen as a referendum on his leadership and a fierce proxy battle with his estranged vice president.

Former Philippine President Rodrigo Duterte, detained in The Hague and charged with crimes against humanity, is on the ballot in Monday’s midterm elections.

Philippine President Ferdinand Marcos Jr has been dealt an unexpected blow in the midterms, with his Senate candidates set to pick up fewer seats than expected, according to early results. The election was a showdown between Marcos and his Vice-President Sara Duterte, daughter of former president Rodrigo Duterte.