Zack Polanski, elected Green Party of England and Wales leader in September 2025 with 84 percent support, faces mounting internal pressure ahead of the October 8 Holborn and St Pancras by-election where he is the candidate. Senior party figures have privately warned that a heavy defeat could trigger leadership questions, given concerns over stalled momentum and resource allocation disputes during the recent Brighton conference. The narrow passage of a contentious motion defining Zionism as racism—passed 1,022 to 813 while Polanski campaigned elsewhere—has prompted resignations, including from Jewish members and the chair of Amnesty International UK, alongside an Israeli entry ban. These events have highlighted divisions between the party's expanded membership and its established direction, with the next scheduled leadership contest less than a year away.