The vice-president of the Philippines, Leni Robredo, has accepted President Rodrigo Duterte’s offer for her to play a lead role in his deadly crackdown against drugs, even though the former human rights lawyer is critical of the campaign and has been warned it could be a political ploy to destroy her.

Robredo said that by agreeing she may be able to save lives from a campaign that has killed thousands of mostly petty drug suspects in purported gun battles with police.

“Many have expressed concerns that this is an insincere offer, that it’s a trap which only aims to undermine and put me to shame,” said Robredo. “While it can be said that this offer is just politicking and that the agencies won’t really follow me and would do everything so I won’t succeed, I’m ready to endure all of these.

“If I can save even one innocent life, my principles and my heart tell me that I should try.”

Duterte’s communications secretary, Martin Andanar, welcomed Robredo’s decision. “We believe that the loudest critics should act beyond mere observers, but be active contributors for change,” he said.

Nicholas Bequelin, an Amnesty official for the region, said: “Vice-president Robredo must be granted power to halt the daily killings and change the deadly command structure we have documented, otherwise this move will be an empty gesture. Her appointment does not change the fact that the Duterte administration’s ‘war on drugs’ amounts to crimes against humanity.”

After Robredo’s criticism of his drug campaign, Duterte formalised an offer to appoint her as one of two heads of an inter-agency committee that includes the police and the military and is tasked with overseeing and coordinating the government’s efforts to combat illegal drugs.

Duterte launched the crackdown after he took office in mid-2016. More than 6,300 mostly petty drug suspects have been killed and about 1.3 million others have surrendered, officials have said. Human rights groups have cited a higher death toll and accused some police of killing unarmed suspects based on flimsy evidence and altering crime scenes to make it look like the suspects violently fought back.

At least two complaints for mass murder have been filed before the international criminal court over the large-scale deaths, but Duterte has vowed to continue with the bloody campaign up to the last day of his presidency in June 2022.

Presidents and vice-presidents are separately elected in the Philippines. Robredo, 58, is a respected former human rights lawyer and political newcomer.