Zack Polanski faces immediate pressure as Green Party leader of England and Wales ahead of the October 8 Holborn and St Pancras by-election, where he is the candidate in a high-stakes contest for Keir Starmer’s former seat. A strong defeat could intensify internal questions about his strategy and authority, though Polanski has stated his position does not depend on the result. Recent party conference proceedings in Brighton saw members pass a contested motion equating Zionism with racism by 1,022 to 813 votes, prompting Israel to bar his entry and drawing criticism from some senior Greens. YouGov polling shows his net favorability has fallen to minus 19 amid broader softening in Green support, while rapid membership growth under his eco-populist approach has not fully translated into consistent electoral momentum. These factors shape trader assessments of near-term leadership stability.