Sen. Leila de Lima on Monday filed a petition against President Rodrigo Duterte before the Supreme Court.
De Lima's petition cites the writ of habeas data, a remedy "available to any person whose right to privacy in life, liberty, or security is violated."
The senator first met women supporters at a restaurant near the SC compound, where she initially was supposed to hold a press conference.
"Enough is enough," she said.
De Lima and her supporters then walked to the SC.
In a press conference after the filing of the case, De Lima noted that her petition is a "novel case" given that the habeas data is rarely used in court.
She said this is "the first of a series of legal offensives" she will file against Duterte. She said the cases would stand as a test against Duterte's presidential immunity.
She said she is doing this because of the attacks that Duterte has launched against her as a person and as a woman.
"Nakasaad po sa petition namin 'yung ilan ilan na okasyon na nagmumura at kung anu-ano po 'yung sinasabi niya tungkol sa aking pagkababae na wala hong kinalaman sa kaniyang posisyon bilang Pangulo," she said. "Na sobra po ang binibitawan niya na mga salita. Na nagpapababa, na binabastos ang aking pagkatao, ang aking pagkababae, gawa nga ng kaniyang personal vendetta laban sa akin."
She added: "This is a test case, this is a novel case of transcendental importance. Ang pinakatanong dito, pwede bang ang isang nakaupong Pangulo ay gamitin ang kaniyang opisina, ang kaniyang kapangyarihan bilang pangulo para magsagawa ng isang personal vendetta laban sa isang tao, laban sa isang babae sa pamamagitan ng ilegal na pangongolekta ng impormasyon tungkol sa pribadong buhay ng isang babae na 'yan."
"'Yong babae na 'yan... ako po ang babae na 'yan, ako po ang public official na 'yan na non-stop po 'yung mga panglalait po sa akin ng Pangulo," she went on.
De Lima's camp said her submission includes a compact disc containing video and audio recordings of Duterte's personal verbal attacks against her in public.
She also submitted an assessment report made by a "respectable psychologist specializing in women's concerns," which details the psychological effect "inflicted" by Duterte's attacks.
The senator said these attacks "blatantly violated" the Code of Conduct and Ethical Standards for Public Officials (R.A. No. 6713) and the Magna Carta for Women (R.A. No. 9710).