The conflict has led to deep splits within Labour.
“How can the Labour Party manage to take a crisis in the Middle East and make it about itself,” grumbled one senior member of the shadow cabinet this week.
It’s a fair question. As innocent civilians continue to die on a daily basis in the ongoing war between Israel and Hamas, Labour has been engulfed by its own internal conflict.
After 12 months in which Keir Starmer has guided his party to a 20-point lead over the Tories and become viewed by many as the prime minister-in-waiting, he faces the biggest test of his leadership since he succeeded Jeremy Corbyn in the wake of the 2019 election.
His troubles started two weeks ago when, during an interview on LBC, he appeared to give his support to Israel cutting off water, fuel and food supplies to Gaza.
By the time his office belatedly tried to explain that he had in fact been supporting Israel’s general right to defend itself, the damage had already been done.
Muslim voters around the country were outraged, and made their views known to their local Labour MPs - including senior members of the shadow cabinet - who, in turn, expressed their own disquiet to Starmer.
In the past week, the row has gained further momentum as demands grow for Labour to support a ceasefire in the war.
A crisis meeting between Starmer and around a dozen MPs and peers did little to calm the tensions within the parliamentary party.
Afterwards, Starmer said he supported a “pause” in hostilities to allow more humanitarian aid to get through to Gaza, but stopped short of calling for a full ceasefire.
Their interventions were met with fury from some Starmer supporters.
One accused them of “political posturing while babies die”.
Another told HuffPost UK: “If you are a serious government in waiting, you can’t allow matters of huge geopolitical importance to be decided or unpicked based on what your members or your constituents lobby you to say. You have to take a proper approach to it. That’s leadership.
“The Tories have spent 13 years jumping on bandwagons like this over every subject and look where it’s got us.”
A shadow cabinet member said: “I’ve had 850 emails on this, the vast majority of them anti-Israel.
“But we’ve got to hold our nerve. It’s a real test of whether we’re a party of government or a party of placards.”
Palestinians search for survivors and the bodies of victims through the rubble of buildings destroyed during Israeli bombardment, in Khan Yunis in the southern Gaza Strip.
There’s no doubt, however, that many in Labour are deeply uneasy about Starmer’s handling of the crisis.
The party lost its majority on Oxford City Council last week after nine of its councillors resigned.
More than 250 Muslim Labour councillors from across the UK have also signed a letter to Starmer calling for a ceasefire.
At Westminster, as many as 100 - half the parliamentary party - are thought to be unhappy with Labour’s current position.
Among those voicing their concerns behind the scenes are shadow postmaster general Jon Ashworth and Shabana Mahmood, the shadow justice secretary and one of Starmer’s closest allies.
“Shabana is under tremendous pressure because of her seat, her own heritage and her seniority within the party,” said one insider. “She’s very, very down and is getting it tough in her constituency.”
Another colleague said: “Shabana is getting it the toughest of anyone and we are all trying to support her.”
In a further sign of the pressure Labour MPs are under, chief whip Alan Campbell this week sent a letter reminding them that security advice was available if they need it.
“Your personal safety should always be paramount for any event you are considering attending,” he said.
Starmer’s office is said to fear the “domino effect” of one frontbench resignation leading to several more.
But one MP suggested that the prospect of a Labour government will ultimately prevent people from quitting.
He said: “Those on the lower slopes of the frontbench might be considering resignation, but they won’t jump from a cable car that’s heading up the hill.”
A Starmer ally said the row was “the price of taking a moral stance” on the Israel-Hamas conflict.
“Thank God Keir is the leader of the party rather than one of the shadow cabinet panickers,” the source said.
“Their default setting is to panic and do whatever they are told to do by those panicking them.”
However, some in the party believe the row has shone an unflattering light on the whole Starmer operation.
“They are finding out having a relationship with your MPs is actually quite important,” said one critic.
A veteran Labour insider said: “It’s a failure on two levels, which speak to a lack of political experience and seriousness.
“Firstly, they react but don’t anticipate, meaning they focus on solving the immediate issue without thinking about future problems which will arise from it.
“Secondly, the political management operation is non-existent and the whips office is invisible. Most of the frontbench, never mind the wider parliamentary party, feel ignored and uninvolved.”
With no sign of the row abating, many are convinced that Starmer will inevitably end up calling for a ceasefire. But one senior shadow cabinet member insisted the leader will ride out the current storm.
“I think it will calm down,” he said. “Keir is in the right position.”
There is little doubt, however, that Starmer is being tested like never before. Whether he passes the examination will tell us a lot about whether he is, in fact, ready to be prime minister.