Labor senator Fatima Payman maintains she voted in line with her convictions and followed her conscience by supporting Palestinian statehood as her colleagues voted against it.
Senator Payman has become the first Labor senator to cross the floor in almost two decades and faces possible expulsion under party rules.
Her vote on Tuesday's Senate motion could cost the West Australian her spot in the Labor caucus.
"My decision to cross the floor was the most difficult decision I have had to make and, although each step I took across the Senate floor felt like a mile, I know I did not walk these steps by myself," she said.
"I've walked with my Muslim brothers and sisters who told me they have felt unheard for far too long and I walked with the people of Palestine.
"For the 40,000 killed (in Gaza), for the hungry and scared boys and girls who now walk alone, without their parents, and for the brave men and women who have to walk alone without their children."
She said she was proud of what she did and believed it aligned with Labor values, with the recognition of Palestine a part of the party's platform.
"I'm bitterly disappointed my colleagues do not feel the same way," she said.
"We cannot believe in a two-state solution and only recognise one."
Senator Payman said she knew the possible consequences of her actions with Prime Minister Anthony Albanese left to decide whether to stand by his senator or expel her from the party.
While Senator Payman believed many people in the party shared her views but did not agree with her methods, she said rank and file members wanted their representatives to do more.
The Greens motion sought to have the upper house declare the recognition of Palestinian statehood as an urgent matter.
It was defeated with Labor and the coalition voting against it, while independent senators David Pocock and Lidia Thorpe joined the Greens and Senator Payman to vote for it.
Greens senator Mehreen Faruqi branded the government's rhetoric against Israel as tepid, saying "all of which Israel has ignored and will continue to ignore".
Labor has affirmed it will recognise a Palestinian state but with no timeline attached.
Foreign Minister Penny Wong said it would form part of a peace process for a two-state solution and could no longer be pushed back until a negotiated peace settlement was agreed.
The coalition's policy was to recognise Palestinian statehood once certain caveats had been met, including Palestinian officials and the Palestinian Authority affirming Israel's right to exist as a democratic and Jewish state.
Palestine's supporters see recognition as locking in a two-state solution as the international community continues to try to negotiate a ceasefire and peace deal between Israel and Hamas.
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, according to Tel Aviv.
Israel's counter-offensive in Gaza has since killed more than 37,000 people, the Hamas-run local health ministry says.
