Senator Fatima Payman, who announced on Thursday she was quitting her party, has now officially joined that well-known club of “Labor rats” – those who have been thrown overboard or jumped ship.

Notable past members include then prime minister Billy Hughes, expelled during the first world war conscription crisis, and Joe Lyons, a minister during the great depression, when Labor fractured.

But the “club” has never had someone like Payman, a religious, hijab-wearing young Muslim woman who reflects one slice of the modern, increasingly diverse Australian community.

Payman, now a crossbencher, said she had been “deeply torn”.  She’d had “immense support” from rank and file Labor members urging her to “hang in there” and fight for change within the Labor. On the other hand she had been pressured  to conform to caucus solidarity and toe the party line.

“I see no middle ground and my conscience leaves me no choice,” she said at her resignation news conference where she performed strongly and answered multiple questions. She was resigning from the Labor Party “with a heavy heart but a clear conscience”.

From Western Australia, Payman has only been in the Senate since the last election. Born in Afghanistan, her family fled the Taliban; her father came to Australia by boat in 1999 and was detained. She said on Thursday:“My family did not flee from a war-torn country  to come here as refugees for me to remain silent when I see atrocities inflicted on innocent people.”

Payman attended the Australian Islamic College in Perth, and then the University of Western Australia. Working as an organiser for the United Workers Union helped elevate her to third place on the WA Labor Senate ticket.

Nationally, Payman hasn’t had a high profile, beyond the usual publicity around her “firsts”, including the first hijab-wearing woman in parliament. Until the last couple of weeks, few people would have heard of her. But for the Israel-Hamas war, that would probably have remained the case for a long time.

For Labor that war – in which Australia has no role or influence – has become a domestic political nightmare. Whether it is the government trying to get its policy pitch  right, or attempting to manage the politics, the conflict has put great strains on Labor.

Internally, in the days before her resignation Payman had support from some Labor Party branches. In the prime minister’s own electorate, the Leichhardt branch passed a motion of “solidarity” with her.

In the run-up to her defection, Labor heavyweights simultaneously briefed against her while declaring that many Labor figures had reached out to her.

Albanese believes the Payman saga amounts to an orchestrated plot that had been in the works for weeks.

Payman rejects that, insisting she finally decided to cross the floor while in the chamber. The government has made much of her not speaking up in the caucus about her concerns. She said she’d had individual conversations with colleagues and had used caucus committee and factional channels to raise the Palestine issue. “I felt I exhausted every opportunity to raise my concerns.”

After her defection, government sources argued the differences between its line and Payman’s position on Palestine was small, revolving around timing. The government totally rejected her claims members had tried to intimidate her.

The claims and counter claims about her conduct often come down to “they say, she says”, and individual perceptions.

The local fallout from the Middle East war is signalling that Australian multiculturalism has moved into a new, more challenging phase, fraying its fibre. As Albanese has repeatedly said, the Middle East war is straining our social cohesion.

This is a particularly worrying development, because multiculturalism has been one of this country’s great achievements. The spectre of a political party or movement arising based around religion raises concerns among many in politics, beyond the possible implications for Labor’s vote.

Muslim activists are organising ahead of the next election, in south western and western Sydney, but what this will amount to is unclear.

Community leaders have recently had meetings (one of them attended by Payman) with Glenn Druery, “the preference whisperer” who has long worked with micro-parties.

“The Muslim Vote” group proclaims itself “dedicated to empowering Australian Muslims in the electoral process”.

Late Thursday The Muslim Vote issued a statement declaring it was “not a political party”. “We support campaigns and candidates across Australia and support anyone who shares our principles of justice and fairness,” the statement said, adding, “The Muslim Vote is not a religious campaign but a political one”.

Labor is fearful, not least because the threat is still inchoate; Labor is unable to judge its nature and potential power to do damage.

The potential “Muslim” vote – to the limited extent such a vote would be solid – is significant in a batch of seats in Sydney’s west and south west, several occupied by ministers.

Labor holds such seats with big majorities and challenges from an organised Muslim vote would seem unlikely to be able to dislodge their members. But they would be disruptive, and would force leading ministers to spend more time in their electorates than they normally would. In Victoria, there is some fear that Muslim pressure could worsen the position of Peter Khalil, in the Melbourne seat of Wills, already under strong pressure from the Greens.

In its last day of the parliamentary session, and hours before  Payman’s statement, MPs were shocked by a protest that saw four demonstrators scaled the security fence to get on to the roof of Parliament House. That fence was erected a few years ago to make the building, where security has progressively increased, impregnable.

Meanwhile inside, the opposition successfully moved a motion in the Senate reaffirming “Israel’s inherent right to self-defence, whether attacked by Hamas, Hezbollah, Iran or any other sponsor of terrorism”. The Greens announced they will put a motion in the Senate at the start of the August sitting calling for the government “to sanction members of the extremist Netanyahu government”, including the prime minister and defence minister.

While this war continues to rage, the fissures it is bringing in Australian politics and society more generally will continue to widen. Even when it finally ends, the divisions and wounds will not be healed easily or soon.

Michelle Grattan, Professorial Fellow, University of Canberra. Republished from The Conversation.