Maria Lourdes Sereno

In a televised public speech in April 2018, Duterte addressed the Chief Justice thus: "So I’m putting you on notice that I am now your enemy. And you have to be out of the Supreme Court." after Sereno accused him of interfering with the case.

After an impeachment process against her began, Sereno took an indefinite leave on March 1, 2018, but maintained she will not resign. She returned from leave shortly after the rest of the Supreme Court made a decision on the quo warranto petition. Deciding on the quo warranto petition en banc the Supreme Court justices voted to remove Sereno from the court on May 11, 2018, by a vote of 8–6.

Sereno filed a motion for consideration but the high court denied with finality Sereno's motion for reconsideration for lack of merit on June 19, 2018 voting 8–6, upholding the quo warranto decision. The ruling also states that no further pleading will be entertained as well as order for immediate entry of judgement.

Senior Justice Antonio Carpio assumed the post of Chief Justice in an acting capacity starting May 14, 2018, following Sereno's removal from office. On the evening of August 25, Teresita de Castro, who only had two months left to serve in office, was appointed by president Rodrigo Duterte as the new Chief Justice. The appointment sparked outrage from the opposition.

On August 30, 2017, at least 25 members of the House of Representatives began the impeachment process against then-Chief Justice Sereno. In addition Solicitor General Jose Calida filed a quo warranto petition to invalidate her appointment as chief justice over alleged lack of integrity. Both the impeachment proceedings and quo warranto petition cites Sereno's alleged failure to properly declare her Statement of Assets, Liabilities and Net worth (SALN) and was also responsible for tax misdeclarations and unauthorized expenses. Sereno has questioned the quo warranto petition saying that she could only be legally removed through impeachment

On August 24, 2012, President Aquino announced his appointment of Justice Sereno as the new Chief Justice of the Supreme Court, replacing Renato Corona, who was removed from office in May 2012 after being convicted in an impeachment trial.

In August 2010, she was appointed Associate Justice of the Supreme Court of the Philippines, its 169th Member and the first appointee to the High Court by President Benigno Aquino III. Sereno, the 13th woman appointed as Justice of the Supreme Court, was the youngest appointee to the court since Manuel Moran in 1945 until Marvic Leonen surpassed her at the age of 49 in 2012.

She was the only female member of the 1999 Preparatory Commission on Constitutional Reform where she headed the commission’s Steering Committee. In the same year, with Justice Jose Campos, Commissioner Haydee Yorac, and other professors from the UP College of Law, she co-founded Accesslaw, a corporation that provided the first annotated electronic research system in Philippine law.

She obtained a Master of Arts in economics from the University of the Philippines School of Economics (also at UP Diliman) in 1992. She earned a Master of Laws from the University of Michigan Law School in 1993.

A scholarship allowed her to apply at the Ateneo de Manila University where she had the options of taking either Political Science or Economics. She opted for the Bachelor of Arts in Economics and graduated in 1980. She finished her Bachelor of Laws degree from the UP College of Law at the University of the Philippines Diliman, graduating as cum laude and class valedictorian, passing the bar in 1984.

Sereno graduated salutatorian from Kamuning Elementary School in 1972 and with honors from Quezon City High School in 1976.

Maria Lourdes "Meilou" Aranal Sereno (Tagalog: [sɛˈrɛnɔ] ; born Maria Lourdes Punzalan Aranal; July 2, 1960) is a Filipina lawyer and judge who served as de facto Chief Justice of the Supreme Court of the Republic of the Philippines from 2012 until her removal in 2018. Appointed as Associate Justice by President Benigno Aquino III in August 2010, she became the second youngest person (at the age of 52) to assume the post of Chief Justice in August 2012. She was removed from office by way of an 8–6 decision by the Supreme Court over a quo warranto petition, rendering her appointment as Chief Justice null and void. Many supporters as well as legal experts regard the removal of Sereno, who opposed President Duterte's declaration of martial law in Mindanao and other executive actions, as politically motivated.

Sereno was born on July 2, 1960, in Manila, to Margarito Aranal, a native of Siasi, Sulu, and Soledad Punzalan, who served as a public school teacher.