Philippine voters appear to have delivered a blow to President Ferdinand Marcos Jr. and a boost to the rival Duterte clan, whose members and allies outperformed expectations in Monday’s midterm elections.

Philippine President Ferdinand Marcos Jr, commonly known by his nickname Bongbong, has been gearing up for a battle that could decide his political future. Monday's midterm elections are, in effect, a showdown between Marcos and his Vice-President Sara Duterte, daughter of former president Rodrigo Duterte.

With temperatures reaching 34 degrees Celsius (93 Fahrenheit) in some places during the day, Comelec chief George Garcia said some voting machines had experienced "overheating". "It's slowing the voting process," he told reporters at a prison in southern Manila where inmates were casting ballots.