The People's Justice Party was to decide later on Tuesday whether to accept the 37-year-old Elizabeth Wong's resignation in the central Selangor state assembly.
It is the latest incident in Malaysian politics to intrude into the private lives of politicians, most of whom have been opposition figures. Among them was People's Justice Party leader Anwar Ibrahim who has been accused of sodomy twice.
The government has denied a role in the scandals, including Wong's pictures.
In an emotional news conference, Wong, a well-known human rights activist, did not deny that the pictures in question were of her.
She said it was "an insidious and underhanded attempt" to smear her reputation, adding that "the real objective is to discredit the party."
"I have done nothing wrong. I wish to state that I am not ashamed of my sexuality as a woman and as a single person. I have broken no law," she said, her eyes brimming with tears.
"In the interest of my party I have decided to offer my resignation," said Wong.
News reports say the photos were believed to have been taken by her ex-boyfriend without her knowledge in her home last year.
She filed a police complaint on Sunday after being informed that a newspaper had received the photographs from unidentified sources.
Wong did not blame the governing National Front coalition directly for her embarrassment, but Sivarasa Rasiah, a leader in her party, was more candid.
"What has happened is clearly motivated. This is gutter politics" by the National Front, he said.
