MANILA - Malacañang on Monday described as “unprecedented” the “quo warranto” petitions filed before the Supreme Court seeking the nullification of the appointment of Chief Justice Maria Lourdes Sereno.

Presidential Spokesperson Harry Roque said it is a “general rule” that as chief justice, Sereno can only be removed through impeachment.

“This is unprecedented. While the normal rule is impeachable officers can only be removed through impeachment, the petitioners, who I believe are fully cognizant of this doctrine, probably feel that under the circumstances the general rule should not be applicable,” Roque said in a news conference in Malacañang.

Roque, nonetheless, said the executive department will follow whatever the high court’s decision will be on the matter. He said the administration will also follow the Senate if it decides to remove Sereno through impeachment.

The Office of the Solicitor General on Monday asked the SC to void Sereno's appointment.

• SolGen seeks nullification of Sereno's appointment

Sereno is "unlawfully holding" her post due to her alleged failure to fully disclose her wealth, according to the petition for quo warranto filed by OSG.

Under Rule 66 of the Rules of Court, a quo warranto proceeding is an action by the government against an individual who “usurps, intrudes into, or unlawfully holds or exercises a public office, position or franchise.”

According to the Solicitor General's petition, Sereno failed to declare her wealth in full during 17 years out of her 28-year teaching stint at the University of the Philippines College of Law.

From 1986 to 2006, Sereno's Statements of Assets, Liabilities, and Net Worth (SALNs) on record only covered 1998, 2002, and 2006.

Lawyer and Marcos loyalist Oliver Lozano also filed a petition before the high court seeking the nullification of Sereno’s appointment.

• Lawyer asks Supreme Court to void Sereno appointment

Former President Benigno Aquino III appointed Sereno to the high court post in 2012 following the ouster of the late chief magistrate Renato Corona, who was removed for undeclared wealth.

Then 52, Sereno was expected to stay in her post until reaching the mandatory retirement age in 2030.

She is currently on indefinite leave as she prepares for a possible impeachment trial.