Philippines VP Leni Robredo
Philippines Vice-President Leni Robredo Ezra Acayan/IBTimes UK

Philippines Vice-President's speech to the UN attacking President Rodrigo Duterte's war in drugs made international headlines, but did not go down well among some of her fellow citizens.

House Speaker Pantaleon Alvarez told CNN Philippines that he will be looking to impeach Vice-President Leni Robredo on the basis that her speech breached public trust.

"If in my research, I can find sufficient evidence to prosecute, we have to see if it can stand trial before the Senate" he said "This is the first time I've seen a top government official smear the country's reputation before the international community," he said.

In the video, addressed to the UN Commission on Narcotics Drug, Robredo talked about the country's "grim statistics" in terms of extra-judicial killings. "More than 7,000 people have been killed in summary executions," she said, adding that trust in the police has plummeted, leaving citizens unsure as to where to turn to. "Our people feel both hopeless and helpless," she said.

The vice-president renounced her post on Duterte's cabinet in December, due to major differences with the president, who barred her from attending cabinet meetings. In her speech to the UN, Robredo appealed to President Duterte, asking him to focus on fighting poverty, upholding basic human rights and instill "hope and inspiration instead of fear" among the Filipino people.

In a scathing column published on the Manila Times on 17 March, former diplomat Rigoberto Tiglao accused Robredo of "lying to the world", inflating the number of people who have died as a consequence of the war on drugs and who have complained to the Commission on Human Rights (CHR).

Tiglao objected to the statistics. In his column, he said the 7,000 number refers to the total murder rate in the country recorded by the Philippines National Police, which does not distinguish between the causes of the murder.

According to him, a closer estimate is that recorded by the Philippines Inquirer newspaper, which is keeping a record of the killings resulting in the drug war. Their latest update, from 16 February, recorded 2,127 deaths since 30 June 2016, of which more than half, (1,104) killed by the police and the rest by unknown hitmen.

He also said that Robredo's claim of 500 complaints issued to the CHR was false, as his sources told him no complaint was filed. "If she wants to continue ranting against Duterte, she has to resign as Vice President, and send the messages like that she sent to the UN as one by a Liberal Party official," he wrote.

The threat to impeach Robredo comes a day after House Speaker Alvarez received a first official motion to impeach President Duterte by Filipino opposition lawmaker Gary Alejano for abuse of power.

The Philippines government is rejecting any accusation of wrongdoing in another controversial case putting the country under the spotlight, the imprisonment of anti-Duterte Senator Leila de Lima on drug trafficking charges, which she disputed.

The Department of Foreign Affairs said a call by the European Parliament for the release of the senator "casts aspersion on Philippine legal processes, its judicial system," the Associated Press reported.