Senator Fatima Payman’s future in the Labor party is now in the hands of her caucus colleagues after she defied her leader and crossed the floor during a vote on Palestine.

The West Australian senator voted against her party in the Senate on Tuesday when she supported a Greens motion to have the upper house declare the recognition of a Palestinian state an urgent matter.

Labor members are expected to follow the party’s position but there is no mandated sanction for crossing the floor. 

It’s the first time a party member has crossed the floor since 2005.

“I said I will follow my conscience,” she said when asked about her decision to cross the floor.

“What our rank and file members have been asking us is for us to do more as a party … that takes pride in our fight towards human rights and being champions of justice.”

Any decision to expel the senator is one for caucus and the senator’s Labor membership will be left in the hands of the national executive.

Asked if Senator Payman should be punished for crossing the floor, Home Affairs Minister Clare O’Neil said “we’ll go through a process” but gave no detail on what that entailed.

“What I think is really obvious here, to everyone that understands this, is this is a really complex topic,” she told Seven’s Sunrise program.

“We are not going to solve peace in the Middle East through Greens motions in the Senate.”

But senior Liberal senator Simon Birmingham said Senator Payman’s actions directly challenged Prime Minister Anthony Albanese’s leadership.

His colleague, Senator Jane Hume said the episode showed Mr Albanese was weak on the issue, adding that it was not the first time Senator Payman had defied her leader.

“Only a month ago, she stood up and gave a press conference where she used … and I won’t repeat the phrase, but a phrase that the prime minister himself says incites violence and anti-Semitism,” Senator Hume told Seven.

“How he deals with it is going to be a test of his leadership.”

The Executive Council of Australian Jewry also condemned the vote to support Palestinian statehood. 

The Australian Federation of Islamic Councils welcomed Senator Payman’s support.

The recognition of Palestinian statehood would set a significant step forward with it being a matter of human rights, dignity and justice that should traverse political lines, council president Rateb Jneid said.

The Greens supported Senator Payman, with Mehreen Farqui – who moved the motion – saying the Labor member had stood by her convictions and showed “real moral courage”.

Labor supports the right of Israel and Palestine to exist as two states and would recognise a Palestinian state although there is no timeline and there are caveats.

“I was not elected as a token representative of diversity, I was elected to serve the people of Western Australia and uphold the values instilled in me by my late father,” Senator Payman said.

“We cannot believe in a two-state solution and only recognise one.”

Senator Payman has also joined with the Greens and crossbenchers to call on the government to take a stronger stance against Israel’s actions in Gaza, with the death toll surpassing 37,000, according to the Hamas-run local health ministry.

A United Nations inquiry found both Israel and Hamas have been responsible for war crimes after the designated terrorist organisation killed 1200 Israelis and took some 250 hostages during an attack on October 7.

The scale of killing in Gaza, use of starvation and failure to supply essentials such as food, water, shelter and medicine were found to be war crimes conducted by Israel.

The federal government has called on Israel to abide by international humanitarian law and said it was “gravely concerned” at the inquiry’s finding.  

Palestinian supporters want outright condemnation and accountability.