Vice President Leni Robredo is stepping down as chair of the Housing and Urban Development Coordinating Council (HUDCC).
The decision was announced on Sunday night, with Robredo to tender her resignation on Monday.
"We had hoped this day would not come... I am tendering my resignation from the Cabinet on Monday, December 5, 2016. With this resignation, you can expect that I will continue to support the positive initiatives of this administration and oppose those that are inimical to the people’s interest," she said in a statement posted on her Twitter account.
Robredo mentioned in her statement that she had been warned of a plot to steal the vice presidency from her.
Robredo said she decided to quit as Housing Secretary after receiving a text message from Cabinet Secretary Jun Evasco Jr. that President Rodrigo Duterte wanted her to "desist from attending all Cabinet meetings starting Monday, December 5."
"This is the last straw, because it makes it impossible for me to perform my duties," she said.
Robredo also cited "major differences" between her and Duterte "in principles and values."
"Since I assumed office, I have been consistent in my opposition to issues such as the burial of former President Ferdinand Marcos in the Libingan ng mga Bayani, extra-judicial killings, reinstating death penalty, lowering the age of criminal liability, and sexual attacks against women," she said.
She added: "But we both had a mandate to serve the people. I had hoped that this shared commitment to the poor and marginalized would transcend the differences between us. So, I took the job of Housing Secretary when it was offered to me."
The Vice President also cited "obstacles" in the HUDCC.
"One, the budget for all key shelter agencies in 2017 has been slashed by more than P19 billion. Two, all our key shelter agency appointment recommendations have not been acted on. Three, the Executive Order designed to make HUDCC effective was not signed," she said.
The head of the Governance Commission for Government-Owned and Controlled Corporations quit his post last October, the first resignation among Cabinet members of Duterte.
On Tuesday last week, National Historical Commission of the Philippines chairperson Maria Serena Diokno resigned from her post in protest of the burial of Marcos in the Libingan ng mga Bayani.
In separate radio interviews, Evasco and Communications Secretary Martin Andanar also cited the "irreconcilable differences" between Duterte and Robredo.
"Wala akong detalye, basta sinabi lang ni Presidente, irreconcilable differences. Tsaka alam naman ng Pilipinas, ng tao ano ang irreconcilable differences nila. Ang mga issue ngayon, si Presidente [nandito] at si VP, sa kabila naman parati," said Evasco.
Evasco said he had earlier tried to call up Robredo, but she would not pick up.
Evasco said they are still not yet looking for Robredo's replacement, but said that when the time comes, the Duterte Cabinet would be "constrained to look for" a replacement.
"[For now] wala naman [kapalit]... tsaka wala naman instruction for her to be terminated sa position. Whatever decision she takes, that's her prerogative," he said.
"I think it's part of the normal administration. If they cannot side with what the President is doing, then they have to resign," Evasco said.
Evasco remained confident that despite her departure from the Cabinet, Robredo would still "be figuring in other important positions, being [the] second highest official."