Senator Fatima Payman says she was “deeply torn” over her decision to quit the Labor Party but her conscience left her “no choice” but to stand up for her beliefs.

Payman ended speculation about her future when she announced her resignation on Thursday afternoon, saying her principles no longer aligned with Labor’s.

“With a heavy heart but a clear conscience, I announce my resignation from the Australian Labor Party,” she said.

“I have informed the Prime Minister that, effective immediately, I will sit on the crossbench to represent Western Australia.”

An at-times emotional Payman said it was the most difficult decision of her life, but she could not stay silent on the deaths in Gaza.

“Witnessing our government’s indifference to the greatest injustice of our times makes me question the direction the party is taking,” she said.

“I am torn, deeply torn.

“On one hand, I have the immense support of the rank-and-file members, unionists, the lifelong party volunteers, who are calling on me to hang in there and to make change happen internally.

“On the other hand, I am pressured to conform to caucus solidarity and toe the party line. I see no middle ground and my conscience leaves me no choice.”

Payman said she had been intimated on all fronts, including by being escorted to Prime Minister Anthony Albanese’s office so she was on “show”. She also revealed she’d received death threats and “confronting” emails.

“[It has been] difficult to say the least, aside from receiving death threats and emails that were quite confronting, especially when it involves my family and saying all sorts of awful things – but we know what we sign ourselves up to when we joined public office,” she said.

She took a jab at the Prime Minister who she said had wrongly accused her of planning her move for a month.

“I did not expect the Prime Minister during QT (Question Time) yesterday to make an assumption – I wouldn’t want to say accusation, but it felt like an accusation – where I have been planning this for a month,” she said.

“Because it is not true. I have not. The vote was purely based on my conscience.

“It was yesterday after QT where I thought this is when I have to make a decision, the ultimatum provided to me because that was the result that came out of my meeting with the Prime Minister at The Lodge on Sunday.”

The Western Australian was suspended from the Labor caucus after she crossed the floor to support a Greens motion on Palestinian statehood and vowed to do so again in the same circumstance.

She has described feeling isolated from her fellow party members after she was chastised by Albanese, raising questions over her future political career.

Albanese used Question Time on Wednesday to make a pointed comment about Payman.

“I expect further announcements in the coming days, which will explain exactly what the strategy has been over now more than a month,” he said.

On Thursday he read out a text message from Payman confirming her resignation.

“It has been an honour and a privilege to serve in the Australian Labor Party,” he read, before ending with her resignation.

Payman has denied plotting her resignation for weeks.

Earlier, Labor MPs said the decision to quit would be up to her.

“That’s a choice for her to make,” Dan Repacholi told Nine’s Today show.

“Fatima has been a great member of the Labor Party and a great senator, and she’s also been a great friend.

“I hope that she does not go, I hope that she’d come and talk to us and want to work together as a team and stays part of Labor.”

Skills Minister Brendan O’Connor echoed the sentiment but urged that any action should not fuel tension among Australian communities.

“I’ve been in Parliament now for more than 20 years, and I’m obliged – like every caucus colleague – to comply with those rules,” he told ABC.

“If a person feels they cannot, then they have to make a decision. There has to be consequences for not working as a team, but it’s a sad situation.”

As the next federal election looms, there has also been speculation that a Muslim party could run its own candidates and challenge Labor voter bases in places such as western Sydney.

Payman said on Thursday she had met the group but had no affiliation with it.

“I’ve only had one meeting with them, like I have many meetings across the board with many community leaders and members,” she said.

She also confirmed a “conversation” with so-called preference whisperer Glenn Druery.

“I am a second-year senator. There is a lot to think about and learn and understand this process. So for me, it was purely a discussion I had, and I will not go into details, but … at this stage [I] do not plan to form a party,” she said.

-with AAP