A former member of the defense team of the late Chief Justice Renato Corona during his impeachment trial warned the Senate that it would likely commit “grave abuse of discretion” if it resists convening as an impeachment court to try Vice President Sara Duterte.

Lawyer Tranquil Salvador III, dean of the School of Law and Jurisprudence of the Manila Adventist College and professorial lecturer of the Philippine Judicial Academy, raised the issue on the heels of reports that the Senate may not convene as an impeachment court if the majority of the senators would vote against it, according to Senator Ping Lacson.

"Can that be a question of grave abuse of discretion? In my opinion, yes,” he said in a radio interview, adding that senators are mandated to do so under the Constitution.

Salvador warned that this would be an “issue of first impression,” and may trigger constitutional concerns.