Sir Keir Starmer is considering putting an amendment to parliament on Wednesday over Labour’s position on the Israel-Hamas war.
The party has been divided over its approach to the conflict, with numerous backbenchers calling for a ceasefire.
But the leadership has stood by its own calls for so-called humanitarian pauses to allow aid and supplies to get into the Gaza Strip – echoing the position of the government.
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The discord within Labour has been ramped up by the prospect of an SNP motion being presented to parliament on Wednesday, giving all MPs an opportunity to vote in favour of a ceasefire – if it is selected by the Speaker.
Such a vote could highlight the level of upset on Sir Keir’s backbenchers, with rumours even shadow ministers could rebel against Labour’s official position.
But now Sky News understands the leadership team are having discussions about putting their own amendment to the House in a bid to maintain party unity.
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Labour insiders made it clear to Sky News’ political editor Beth Rigby that if frontbenchers defied the party position and voted with the SNP, they would have to stand down.
And one Labour adviser also told Sky News: “The order at the moment is if you’re on the frontbench and you vote for [the SNP amendment] you won’t be on the frontbench anymore.”
Another party source said a number of ministers may resign in advance, adding: “Maybe [a Labour amendment] will be enough for some, but it won’t be enough for a lot.”
Sir Keir’s position on a ceasefire in Gaza has followed much of the international community, including the UK and US governments.
Speaking at an event a fortnight ago where he attempted to draw a line under the mutiny in his party, the Labour leader said a ceasefire “always freezes any conflict in the state where it currently lies”, adding: “That would leave Hamas with the infrastructure and the capabilities to carry out the sort of attack we saw on 7 October.
“Attacks that are still ongoing. Hostages who should be released still held. Hamas would be emboldened and start preparing for future violence immediately.”
However, a number of councillors have quit the party over his stance, and one shadow minister, Imran Hussain, also resigned his post.
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Earlier in the Commons, there appeared to be little shift in position from shadow foreign secretary David Lammy.
He said the current short pauses in the Israel-Hamas conflict were “clearly not enough” to help those trapped in Gaza, and pushed for a “full, comprehensive and immediate humanitarian pause in fighting”.
Speaking about a possible motion on Wednesday, a Labour figure said: “We want to table something Labour MPs can vote for that is consistent with our policy while reflecting ongoing concerns on the ground.
“We would want people to vote for our amendment and vote against the SNP amendment. Why support SNP political game playing?”
But SNP sources have said Wednesday’s vote would not be a one off, and they would keep up the pressure on Sir Keir and his MPs to back a ceasefire – drawing a dividing line between the two parties.