The vice-president of the Philippine resigned from a cabinet post on Monday, citing “major differences in principles and values” with President Rodrigo Duterte and an unspecified plot to remove her from the vice presidency, reports The Guardian.

Leni Robredo, a human rights lawyer and respected political newcomer, tendered her resignation as housing secretary in a letter to the president but will stay on in her elected post as vice-president.

In the Philippines, presidents and vice-presidents are elected separately and have often come from rival political parties, as is the case with Duterte and Robredo.

“I will not allow the vice-presidency to be stolen. I will not allow the will of the people to be thwarted,” Robredo said in a statement before her resignation. “I will continue to serve the Filipino family and fulfill their dream for a better life.”

Her departure comes amid a political storm for Duterte over his decision to allow the burial of long-dead dictator Ferdinand Marcos in the country’s “heroes’ cemetery” and a bloody crackdown against illegal drugs that has alarmed western governments and human rights watchdogs.

Robredo is the second key official to resign from Duterte’s administration in less than a week. Maria Serena Diokno quit as head of the government’s historical commission on Tuesday in protest at Duterte’s decision to allow Marcos’s burial in the hallowed cemetery.

Robredo cited her opposition to the burial, the drug killings, Duterte’s plan to reimpose the death penalty and “sexual attacks against women” among the issues on which she differed with Duterte, who took office in June.

The last straw, she said, was when she was notified on Saturday by cabinet secretary Leoncio Evasco Jr through a text message about the president’s order for Robredo “to desist from attending all cabinet meetings”, starting on Monday.