MANILA- Lawyer Barry Gutierrez will represent minority senators in the next round of Supreme Court oral arguments on their petition to invalidate the Philippines' withdrawal from the treaty that established the International Criminal Court (ICC).

Gutierrez, spokesperson of opposition leader Vice President Leni Robredo, formally entered on Wednesday his appearance as counsel for Senate Minority Leader Franklin Drilon and Senators Francis Pangilinan, Bam Aquino, Leila de Lima, Risa Hontiveros, and Antonio Trillanes IV.

Formally entered my appearance this afternoon as counsel for Petitioner-Senators in the case they filed before the Supreme Court challenging the validity of the Philippines’ withdrawal from the Rome Statute of the International Criminal Court. Oral arguments continue on Sept 4.

— Barry Gutierrez (@barrygutierrez3) August 29, 2018

The senators in March this year questioned President Rodrigo Duterte's move to pull the Philippines out of the ICC, where he faces complaints over deaths in his fierce war on drugs.

In their petition, the lawmakers argued that the withdrawal should be invalidated as the Senate did not concur through a two-thirds vote.

• Senators skip SC oral arguments on PH withdrawal from ICC

The minority lawmakers had earlier wanted De Lima, currently detained on drug charges, to argue the case but the high court denied their plea.

• Senators skip SC oral arguments on PH withdrawal from ICC

The high court on Tuesday began hearing arguments on petitions challenging Duterte's decision and will continue on Tuesday, Sept. 4.

• Supreme Court begins oral arguments on ICC withdrawal