In line with electoral law, Labour cannot replace Ali with another candidate because the deadline passed on 2 February. He will stand as a Labour candidate on the ballot paper, but if elected he will not hold the party whip and will sit as an independent MP.
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Senior party MPs and members had urged the leadership to confirm Ali would be disciplined if he won the byelection as comments he had made soon after the 7 October attacks surfaced over the weekend. In them, he suggested Israel had deliberately relaxed security after warnings of an imminent threat.
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A local Labour insider said that some activists will seriously consider throwing their support behind Simon Danczuk, the disgraced former Labour MP for Rochdale who was suspended from the party after sending inappropriate messages to a teenager. “Simon may be the best way of keeping [George Galloway, who is running as a Workers party candidate in the byelection] out,” a source said. “It’s the devil and the deep blue sea.”

Danczuk, who is standing for the populist Reform party, said that Labour should now take down posters and rip up leaflets supporting Ali, and ensure their activists no longer campaign for him.

https://www.theguardian.com/politics/2024/feb/12/labour-withdraws-support-for-rochdale-candidate-after-israel-gaza-remarks