Senator Fatima Payman has quit the Labor Party effective immediately and moved to the crossbench as an independent.
The West Australian Senator announced her decision days after she was suspended for crossing the floor and voting in favour of a Greens motion to recognise Palestine as a state.
“I do not believe my principles align with those of the leadership of the Labor Party,” she said.
“With a heavy heart but a clear conscience, I announce my resignation from the Australian Labor Party.
“I have informed the prime minister that, effective immediately, I will sit on the crossbench to represent Western Australia.”
Payman said it was the most difficult decision she has made but said her stance on Palestine was not a matter she could compromise on.
Australia’s first hijab-wearing senator broke more than 100 years of protocol by voting against her party last week.
She was then indefinitely suspended.
Since the fallout of her defiance, Payman said she and her family have received death threats and confronting emails.
She added she felt intimidation from her colleagues, including some not wanting to sit next to her in the chamber and other stand-up tactics.
“And also controlling and constantly pushing me for an answer when I had not made a decision about whether I would cross the floor,” she said.