The Philippines' chief justice has vowed to fight "until the end" the impeachment complaint against her, despite calls from allies of President Rodrigo Duterte for her to resign.

In a speech on Monday, Lourdes Sereno said giving up her position will erode the independence of the country's highest court, and "embolden those who demand a subservient judiciary".

"I will not resign," she said. "Without the slightest doubt, the right thing to do is to fight this impeachment to the end."

Sereno was forced to go on leave by her fellow justices in late February in advance of her impeachment proceedings.

On Thursday, members of a committee in the House of Representatives endorsed a complaint against her for a full vote on the third week of March.

A Senate trial is expected to follow as soon as the impeachment is approved.

A case is also pending before the Supreme Court asking that her appointment be voided.

Sereno, who is an appointee of Duterte's predecessor Benigno Aquino, is accused of failing improperly declaring her income when she was applying for chief justice, and for abusing her position as head of the court.

She has denied all the allegations. Her supporters said she is being targeted for standing up to the president and his deadly war on drugs, which has left thousands of people dead.

During Duterte's first year in office, he clashed with Sereno, after the president released a list of supposed judges linked to the drug trade.

In response, the chief justice said suspected judges should not surrender to authorities, unless a warrant of arrest is issued against them.

Defying Duterte

That angered Duterte, who then threatened to declare martial law and order "everybody" in the executive branch of government "not to honour" Sereno.

Sereno later voted in the minority against Duterte's declaration of martial law in the southern island of Mindanao and the president's decision to extend full military honours to during the burial of late dictator Ferdinand Marcos.

She later came under political attack by allies of the president, who dominate both chambers of the Philippine Congress.

During the committee impeachment hearing, which lasted for months, several House members urged Sereno to resign, to spare the country from a protracted constitutional crisis.

On Monday, Sereno said resigning would have been an easier option for her.

"But I do not make choices in life on the basis of what is the easier option, but what is the right thing to do."

She said her resignation would "invite the kind of extra-constitutional adventurism that treats legal rights and procedures as mere inconveniences that should be set aside when it suits the powers that be".

The Supreme Court is also divided on Sereno, with some justices, judges and employees calling for her resignation.

Sereno was appointed chief justice after her predecessor was found guilty following an impeachment trial in 2012.