MANILA - Chief Justice Maria Lourdes Sereno on Monday accused Associate Justice Teresita Leonardo-De Castro of harboring resentment against her, in a public acknowledgement of divisions in the tribunal.

De Castro and 4 other justices had testified in the impeachment proceedings against Sereno, accusing her of bypassing colleagues in the issuance of court orders and failing to submit requirements when she applied for her post in 2012.

The Chief Justice last week sought to disqualify De Castro's group from participating in separate quo warranto proceedings to nullify her appointment.

Sereno said some of her colleagues had resented her for issuing dissenting opinions when she was still associate justice. She said she tried to patch up their relationship days after her appointment as the country's top judge, but De Castro allegedly rejected her efforts.

"Bagamat karamihan sa kanila ay nagsabing sige, magko-cooperate tayo,may isa pong justice, si Justice Teresita De Castro, ang sinabi po sa akin, 'I will never forgive you for accepting the Chief Justice-ship,'" Sereno said during a Day of Valor program organized by the Movement Against Tyranny.

"Sinabi po niya, 'You should not even have applied in the first place,'" she added.

(Although most of them said, 'All right, we will cooperate,' there was one justice, Justice Teresita De Castro, who said, 'I will never forgive you for accepting the Chief Justiceship.' She said, 'You should not even have applied in the first place.)

Watch more in iWantv or TFC.tv

De Castro, who also applied for Chief Justice in 2012, had said Sereno should not have been among the candidates for her post because she failed to submit her statements of assets, liabilities and net worth (SALN).

• Sereno should not have been Chief Justice candidate: colleagues

Sereno, who has denied any wrongdoing, previously slammed individuals who were "harassing" and "bullying" her to unseat her, but had never spoken out against any Supreme Court colleague before Monday's speech.

• Sereno downplays SC 'infighting'

The High Court is set to hold oral arguments on the quo warranto petition on April 10, Tuesday.

Sereno has been on leave from her duties at the Supreme Court since March in preparation for the ouster bids against her.

The country's first female chief justice was expected to stay in her post until reaching the mandatory retirement age in 2030.