Metro Manila (CNN Philippines) — The chairperson of the National Historical Commission of the Philippines (NHCP) resigned on Tuesday over the controversial burial of former President Ferdinand Marcos at the Libingan ng mga Bayani.

Maria Serena Diokno said the burial of Marcos in the heroes' cemetery last November 18 was a mockery of the 1986 People Power revolution and the country's fight for freedom.

"The burial of Ferdinand Marcos in the Libingan ng mga Bayani is wrong; it denies our history, erases the memory of lives lost and destroyed, mocks the collective action we took to oust the dictator, and denigrates the value of our struggle for freedom," Diokno said in a statement.

Her reasons for resignation echoed the sentiments of the mass protest actions from anti-Marcos groups after the burial. Another anti-Marcos rally is scheduled for November 30.

The NHCP chair blamed President Rody Duterte for "being legalistic" when he championed the burial of Marcos in the heroes' cemetery.

Read: Duterte: If Marcos was no soldier, no president - I'll step down

President Duterte could have "taken the higher ground, but he chose not to," Diokno said.

She had written a letter to Duterte, urging him to stop the burial.

"For a moment I thought I could remain at the National Historical Commission of the Philippines and protect our history from those in and out of government who attempt to deface it," Diokno said.

Diokno said she hopes the youth, many of whom joined the anti-Marcos protests, will " guard our history."

Ending her statement, Diokno took a swipe at 21 years of the Marcos regime which included nine years of Martial Law: "Never again will we allow any remnant of the authoritarian past to take hold of our country."

LOOK: Protesters gather at EDSA to condemn Marcos burial

The NHCP is a government agency tasked with promoting, conserving, and preserving Philippine history and cultural heritage.

One of its aims is to "inculcate awareness and appreciation of the noble deeds and ideals of our heroes and other illustrious Filipinos."

Diokno is the daughter of former senator and nationalist Jose "Pepe" Diokno. The elder Diokno was detained for two years during the Marcos regime. He was also one of the leading opposition figures in protests that culminated in the 1986 People Power revolution which ousted Marcos.

The burial of Marcos followed a Supreme Court decision that removed any legal obstacles to the strongman's burial in the Libingan ng mga Bayani. The burial was one of President Duterte's campaign promises in the runup to the May presidential elections, which he won with majority of the votes.

Fellow board member resigns

Following Diokno's resignation, NHCP commissioner and board member FrancIs Gealogo revealed his resignation because of the Marcos burial.

On his Facebook page, Gealogo shared his resignation letter addressed to President Duterte, dated November 19.

"Now that our Chair has officially tendered her resignation, I can now make public this letter that I submitted the day after the burial," he said.

In his letter, Gealogo defended the NHCP's stance against the burial. "I believe that the Commission's stand opposing the burial of Ferdinand E. Marcos Sr. at the Libingan ng mga Bayani is based on solid historical research and is made as part of the mandate of the Commission to clarify issues pertinent to historical questions that confront our society."