PRESIDENT Rodrigo R. Duterte’s push to restore the death penalty for drug trafficking, plunder and other heinous crimes, might find it difficult to hurdle the Senate, according to a lawmaker who filed the bill.

Senator Christopher Lawrence T. Go, the president’s former aide, told reporters at a briefing yesterday he was “not very confident” that his measure would get enough backing. To date, only Senate President Vicente C. Sotto III has expressed support, he said.

“I call on my fellow senators to support the bill,” Mr. Go said. “If they have nothing to hide, they have nothing to fear,” he said in Filipino.

Mr. Sotto in a statement said reviving capital punishment could move faster in Congress if it is confined to high-level drug traffickers.

Covering plunder and other heinous crimes “will make committee and plenary debates longer due to expected intense debates between advocates and critics.”

Senator Juan Miguel F. Zubiri in an interview with the ABS-CBN News Channel said the numbers for and against the bill are about even now. The lawmaker, who is against the measure, said he won’t sit on the proposal as the majority leader

Mr. Duterte in his annual address to Congress on Monday said drug traffickers must be put to death, noting that the illegal drug menace persists despite his deadly war on drugs that has killed thousands.

The Philippines under then President Gloria Macapagal Arroyo suspended capital punishment in 2006 through a law. Before that, she commuted the death sentences of 1,230 inmates to life imprisonment, which Amnesty International said was the “largest ever commutation of death sentences.” — ALB