President Rodrigo Duterte. Jonathan Cellona, ABS-CBN News

MANILA- (UPDATE) President Rodrigo Duterte on Wednesday was slapped with a "quo warranto" petition at the Supreme Court on allegations that his certificate of candidacy during the 2016 presidential elections was "illegal."

Suspended lawyer Elly Pamatong questioned before the Supreme Court (SC) on Wednesday Duterte’s authority to hold the position of president.

In a 5-page petition for quo warranto, Pamatong, who ran for president in 2004 and 2010 but was declared a "nuisance candidate," called Duterte a “usurper” because the certificate of candidacy (COC) the latter filed in 2015 was “not allowed by law.”

“Prior to the elections on May 9, 2016, Rodrigo Roa Duterte withdrew his COC for mayor in Davao City and, thereafter, filed another COC for another position or for the position of the Presidency. According to the Comelec this process is not allowed by law,” the petition stated.

“Under the law, a candidate who withdraws his COC for one position cannot thereafter file a COC for another position,” it added.

Pamatong did not state what law he was referring to.

Under the Rules of Court, those who may file a quo warranto petition are the solicitor general, public prosecutors, and a person claiming the usurped public office or position.

Pamatong is none of the above.

Duterte was then “substitute candidate” for PDP-Laban partymate Martin Diño.

Pamatong pointed out that Duterte’s COC was filed “late” and that it “was never approved by the Comelec (Commission on Elections).”

This, despite the Comelec decision to dismiss a disqualification case against then-presidential candidate Duterte.

Malacañang on Wednesday expressed confidence that the high court will decide correctly on the petition.

"We respect the Court as an independent institution. We are confident it will render the correct and wise decision. We're confident though that it's utterly bereft of legal and factual merit," Presidential Spokesperson Harry Roque said in a statement.

Last month, the Philippines ousted its first impeachable official by means of granting a quo warranto petition.

In its ruling, the high court said its grant of a quo warranto plea to oust Maria Lourdes Sereno as Chief Justice seeks to ensure that “only qualified individuals” hold public office, asserting that impeachment is not the sole means to remove an impeachable officer.