Labour chair Bridget Phillipson called the Green policy "shameful" and said it underlined the importance of Labour’s efforts to tackle antisemitism under former leader Jeremy Corbyn. One Labour minister told the Guardian they could not foresee how the two parties could work together, while a government official said Labour should formally rule out any future coalition or arrangement.
There is also internal pressure on the Liberal Democrats, with senior party figures calling on them to end their coalition with the Greens in Southwark, formed after May’s local elections. Both parties have issued a joint statement against antisemitism since the Green vote.
The Green motion, passed at the party’s conference on Sunday, has drawn sharp criticism from Labour. The party sees the issue as a way to simplify its political argument against the Greens, who have increasingly tried to attract disillusioned Labour voters from the left.
The immediate test will be Thursday’s byelection in Holborn and St Pancras, where Polanski is standing. Labour is considered the favourite, but the Greens have poured significant resources into the contest. Polanski told the Guardian the race was "really on a knife-edge".