Fifty Labour members have resigned in protest after the party prevented Muslim candidate Faiza Shaheen from running as its candidate in the Chingford and Woodford Green seat.
Shaheen was deselected last month despite beating other Labour candidates to stand in the London constituency where she was raised.
The party deselected the academic over a series of "likes" on social media platform X, which included support for the Boycott, Divestment and Sanctions (BDS) movement, praising former Labour leader Jeremy Corbyn and supporting a friend's decision to stand for the Green Party.
In an open letter, 50 former Labour members from Shaheen's local party condemned the party's "cynical ploy".
"Our democratically elected candidate for Chingford and Woodford Green, Faiza Shaheen, has been deselected in an appalling and unfair manner," the letter says.
The members add that they will be campaigning to elect Shaheen as an independent candidate against incumbent former Conservative minister Iain Duncan Smith.
In 2019, Smith fought off a challenge by Shaheen to keep his seat with a majority of 1,262 votes but in 2024, with public opinion strongly against the Tories, it was expected that he would lose the seat to Labour.
Shaheen's decision to stand as an independent means the anti-Conservative vote will now be further split, increasing Smith's hopes of remaining an MP.
In a statement earlier in June, Shaheen said she would stand as an independent, saying residents of the constituency had been "disenfranchised".
"I have reached this decision following hundreds of messages from people in my community, who say there are no options left for them. They are tired of the Tories but now feel they can’t trust Labour," she said.
In the years since he became Labour leader, Keir Starmer has launched a crackdown against supporters of the former leader Jeremy Corbyn.
A number of candidates seen as being on the left have been deselected, including Corbyn. Under Starmer, the party has shifted its economic position to the right, while also adopting a pro-Israel foreign policy.
Middle East Eye has asked the Labour Party for comment.