Manila, Sept. 8 -- The Senate impeachment court will seek the guidance of legal experts before voting on whether to retain the 16-vote threshold for conviction in Vice President Sara Z. Duterte's impeachment trial, presiding officer Francis Escudero said Tuesday.

Before senator-judges decide, the court will hear from amici curiae or friends of the court, tentatively on Sept. 16, and hold oral arguments for the prosecution and defense on Sept. 23

Escudero said the court is considering retired Supreme Court justices and constitutional law experts as amici curiae, although no invitations have yet been issued.

"We will be enlisting the opinion and assistance of amici curiae, or friends of the court, so to speak, in order to give their opin...