Imran Hussain, MP for Bradford East, said he was “deeply troubled” by the Labour leader’s stance on Israel’s actions and the lack of call for a ceasefire.
He told Starmer his view on the “humanitarian catastrophe” differs “substantially from the position you have adopted”.
Hussain said quitting his role as shadow minister for the new deal for working people would allow him to “strongly advocate” for a ceasefire.
Representing the first Labour shadow minister to resign over the issue, Hussain’s move may prompt other dissatisfied frontbenchers to follow suit.
His current position is to support “humanitarian pauses” to let aid get to Gaza.
Hussain announced his decision via a resignation letter to Starmer published on social media.
It read: “Over recent weeks, it has become clear that my view on the ongoing humanitarian catastrophe in Gaza differs substantially from the position you have adopted.
“A ceasefire is essential to ending the bloodshed, to ensuring that enough aid can pass into Gaza and reach those most in need, and to help ensure the safe return of the Israeli hostages.”
He said he could not “in all good conscience” push for a cessation of hostilities while remaining part of the frontbench.
The MP singled out the Labour leader’s interview on LBC in which he appeared to suggest that the Israeli government had a right to withhold water and power from citizens in Gaza – a suggestion Starmer has said has been misinterpreted as he has sought to clarify his remarks.
The Labour leader has said he understands the calls for an immediate ceasefire, but believes that would simply allow Hamas to regroup and mount more attacks on Israel.
He said he would only support a cessation once the Israeli hostages currently being held in Gaza are released and Hamas’ military capabilities are degraded.
More than 30 Labour councillors have so far quit the party, while 15 shadow ministers at Westminster have also broken ranks to call for a ceasefire.