MANILA: A second impeachment complaint was filed on Wednesday against Philippine vice-president Sara Duterte over her alleged misuse of public funds and refusal to defend her budget before Congress.

The complaint, filed by leftist groups at the House of Representatives, adds to a growing list of cases and investigations against Duterte following her threat last month to have President Ferdinand Marcos Jr., his wife and cousin who is House speaker, assassinated if she herself were to be killed.

Law enforcers are investigating Duterte for possible criminal cases over her threat.

Philippine police have already filed a formal criminal complaint of assault, disobedience and coercion against her over recent incidents in the lower house of Congress and at a hospital. She denies wrongdoing.

The second impeachment complaint accuses Duterte of "betrayal of public trust" in misspending 612.5 million pesos (US$10.49 million), ordering officials under her office to forge reports to cover-up the alleged misuse and refusing to defend her budget before Congress.

The complainants said the Philippine constitution "does not permit such cynical disregard for public trust".

"It does not allow the Vice-President to treat public funds as a personal war chest while stonewalling all attempts at oversight."

Philippine civil society groups, religious leaders and former government officials lodged the first impeachment complaint against Duterte on Monday, accusing her of incompetence, graft and amassing ill-gotten wealth while in office.

At least a third of the 308-member House of Representatives must vote in favour of the impeachment complaint to be transmitted to the Senate.

Senators will then convene as an impeachment court. A conviction requires approval of two-thirds of the 23-member upper Congress. The Senate could remove her from office and disqualify her from holding public office if convicted.

Duterte is also the subject of a heated congressional investigation accusing her of misusing confidential funds in the vice-president's office and during her stint as education minister. Duterte, who resigned in June, has denied wrongdoing.

Policy differences between her and president Marcos include disagreements on South China Sea policy and the campaign against illegal narcotics.

The rift led to the collapse of a powerful alliance between their families that propelled Marcos' landslide win in the 2022 elections.

 - Reuters