More than 68mn Filipinos are heading to the polls in pivotal mid-term elections that could reshape the country's political future and determine the balance of power between its two most dominant dynasties, the BBC reports.

The vote comes at a critical juncture, just weeks after the dramatic arrest and transfer of former president Rodrigo Duterte to the International Criminal Court in The Hague. The arrest, carried out under international pressure over alleged crimes against humanity linked to his controversial war on drugs, sent shockwaves through the Philippine political establishment that continue to reverberate. Duterte has repeatedly denied the allegations, but his sudden detention has intensified political tensions.

At the centre of the mid-term contest is the escalating rivalry between President Ferdinand "Bongbong" Marcos Jr and Vice-President Sara Duterte, the former president’s daughter. The Senate races, in particular, have become a proxy war for control between their rival camps.

If candidates aligned with Marcos win a majority in the Senate, analysts say it could clear the way for an impeachment trial against Duterte. She has faced mounting allegations over the alleged misuse of state funds – accusations she strongly denies. An impeachment would block her path to a widely expected presidential run in the 2028 presidential elections.

Voters are also choosing representatives for the 317-member lower house of Congress, as well as hundreds of governors, mayors and city councillors across the archipelago. Polling stations opened at 07:00 local time and will close at 19:00, with unofficial results expected shortly thereafter.

The detention of the elder Duterte has added an unpredictable element to the elections. While some see it as a long-overdue step toward justice for many killed under his regime, others have rallied around the Duterte name, potentially boosting support for Sara Duterte’s allies.