It comes as three other frontbenchers, Naz Shah, Helen Hayes and Afzal Khan, also broke ranks with their party leader and signalled plans to vote for an SNP amendment to the King’s Speech backing a ceasefire.
Yasmin Qureshi confirmed that she would step down as shadow women and equalities minister, ahead of the Commons vote.
In a post on social media, she said: “The scale of bloodshed in Gaza is unprecedented. Tonight, I will vote for an immediate ceasefire.
“We must call for an end to the carnage to protect innocents lives and end human suffering.
“With regret, I have stepped down as Shadow Women and Equalities Minister.”
Labour frontbenchers are facing the sack if they back the amendment, as Sir Keir bids to avoid a damaging split in his parliamentary party.
Labour MPs have been ordered to abstain on the SNP move and have instead been told to back Sir Keir’s position calling for longer “humanitarian pauses” rather than a ceasefire.
SNP Westminster leader Stephen Flynn has said Parliament must “show moral leadership” and vote in favour of backing an immediate cessation of hostilities.
Labour frontbenchers who rebel to back a rival amendment would normally face the sack for breaking the party whip.
The resignation by Ms Qureshi comes after Imran Hussain also quit the frontbench earlier this month over Sir Keir’s stance on the Gaza war.
