Lawmakers also propose to cut the budget of the nation's human rights commission to $20 over its investigations of the drug war killings.
Philippine lawmakers have moved to cut the budget of the nation's human rights commission to $20 and impeach the Supreme Court chief justice in what critics on Wednesday labelled part of a slide towards dictatorship.
President Rodrigo Duterte directly drew a link between Tuesday night's vote to cut the Commission on Human Rights' (CHR) annual budget from 678 million pesos ($1.3 million) to 1,000 pesos ($20) and its investigations of the drug war killings and related criticism by its chairman.
Police have reported killing more than 3,800 people in anti-drug operations since Duterte assumed office 15 months ago.
Many thousands of others have been killed in unexplained circumstances.
The twin votes in the House of Representatives added to a growing climate of fear that Duterte is determined to silence anyone critical of his war on drugs.
Duterte's critics and allies in the Senate vowed on Wednesday to block the lower house move to slash the annual budget of the CHR.
Vice President Leni Robredo said the lawmakers' move effectively abolishes the CHR, a constitutional body.
The commission is one of several independent government bodies set up by the constitution to check the power of the executive branch, which controls the country's police and military forces.
The Supreme Court is meant to be another safeguard.
The Senate still has to review and endorse the vote to slash the rights commission's budget.
Vote to impeach chief justice
Duterte's allies in the lower house's justice committee on Wednesday also voted to impeach its chief justice after determining corruption allegations against her had substance.
The chief justice, Maria Lourdes Sereno, has been another critic of the drug war.
She wrote Duterte a letter last year expressing concern over him publicly naming seven judges as being involved in the drug trade, warning it made them vulnerable to being killed.
Duterte responded by threatening to declare martial law if Sereno continued to interfere in his drug war.
Should the entire house endorse the justice committee's findings against Sereno, the Senate would convene as an impeachment court.