MANILA - (2nd UPDATE) The Office of the Solicitor General on Monday asked the Supreme Court to void Chief Justice Maria Lourdes Sereno's appointment, the second legal challenge against the country's top judge.

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. The petition cited the chief justice for "usurpation of a public office."

The Chief Justice went on indefinite leave last week as she prepared for a possible impeachment trial at the Senate on similar allegations of misdeclaration of assets.

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.

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Public officials are required under the law to file SALNs.

"The blatant disregard by respondent Sereno to comply with the requirements of the law and Constitution proves her lack of integrity," Solicitor General Jose Calida said in a press conference.

"Hence, she is unlawfully holding the position of the Chief Justice of the Supreme Court," he added.

When Sereno applied for chief justice in 2012, the mandatory submission of SALNs for a period of 10 years was a requirement instituted by the Judicial and Bar Council, the body that screens and shortlists applicants for the judiciary, according to the OSG.

For failing to meet the SALN requirements, Sereno failed to meet the constitutional requirement of "competence, integrity, probity, and independence" for officials of the judiciary, the OSG said.

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QUO WARRANTO, IMPEACHMENT

BASAHIN: Hinihiling ng OSG sa Korte Suprema na ideklarang walang bisa ang pagkakatalaga kay CJ Maria Lourdes Sereno at mapaalis siya sa puwesto | via @zhandercayabyab pic.twitter.com/7IhvMyIJoB

— DZMM TeleRadyo (@DZMMTeleRadyo) March 5, 2018

The OSG said its "quo warranto" petition against Sereno should be treated separately from the impeachment proceedings at the House of Representatives.

The impeachment complaint questions her alleged violations and offenses after her appointment as Chief Justice, while the quo warranto case questions her eligibility for the post prior to appointment, the OSG said.

"If we can prove that she's unlawfully holding the office because of lack of eligibility, then the impeachment must yield to the Supreme Court to discover the quo warranto case," said Calida.

The OSG said that while Sereno is an impeachable officer, she, like the President or Vice-President of the Philippines, may be subjected to quo warranto proceedings.

Guidelines for "quo warranto" proceedings, based on 2010 rules of the Presidential Electoral Tribunal, "may be applied by analogy" to Sereno, the OSG said.

"The Court recognizes the availability of quo warranto against an impeachable officer. In other words, respondent cannot claim that as Chief Justice, she can only be removed by impeachment under Section 2, Article XI of the Constitution," according to the petition.

Calida rejected opposition Rep. Edcel Lagman's claim that the quo warranto is past the 1-year prescription period.

“It (prescription period) starts upon the discovery of the ineligibility and it is only discovered this year,” the government's top lawyer said.

With reports from Ina Reformina and Adrian Ayalin, ABS-CBN News