Eight MPs defied Sir Keir Starmer to back a Commons vote calling for a ceasefire in Gaza.
Four shadow ministers, including Jess Phillips, Yasmin Qureshi, Afzal Khan and Paula Barker, resigned on Wednesday afternoon after deciding to support an SNP amendment to the King's Speech supporting the ceasefire.
Other frontbenchers: Rachel Hopkins, Sarah Owen, Naz Shah and Andy Slaughter. they also face dismissal after cracking the party whip to support the amendment.
MPs voted by 293 to 125, a majority of 168, to reject an amendment to the SNP's King's Speech calling for “all parties to agree to an immediate ceasefire” in Gaza.
Labor MPs had been ordered to stay away from the SNP's move and instead told to support Sir Keir's position calling for longer “humanitarian pauses” instead of a ceasefire.
In a statement after the vote, Sir Keir said he regretted that his party colleagues did not support his position.
“Along with leaders around the world, I have called for international law to be respected, for humanitarian pauses to allow access to aid, food, water, utilities and medicine, and have expressed our concerns about the scale of the loss civilians.
“Much more needs to be done in this regard to alleviate the humanitarian crisis unfolding in Gaza.
“And in addition to dealing with the present, every leader has a duty not to return to a failed strategy of containment and neglect, but to forge a better and more secure future for both Palestinians and Israelis.
“I am sorry that some colleagues felt unable to support the position tonight. But I wanted to be clear about where I stood and where I will stand.
“Leadership is about doing the right thing. This is the least the public deserves. And the least that leadership requires.”
Ms Phillips, a high-profile frontbencher, said it was with a “heavy heart” that she resigned.
“I tried to do everything I could to ensure that this was not the outcome, but it is with a heavy heart that I am stepping down from my position in the Home Office shadow team.
“On this occasion I must vote with my constituents, my head and my heart which has felt like it has been broken for the last four weeks by the horror of the situation in Israel and Palestine,” she said in a letter to her party. leader.
The multiple resignations come after Imran Hussain resigned from the front bench earlier this month over Sir Keir's stance on the Gaza war.