Zack Polanski has led the Green Party of England and Wales since winning the leadership election in September 2025 with roughly 85 percent of the member vote, replacing the prior co-leader model and overseeing rapid membership growth alongside gains in local elections and a Westminster by-election. Recent party conferences and internal motions have raised concerns about potential stagnation amid a new Labour government, while isolated controversies—including a returned donation and questions over residency—prompted limited criticism but no formal challenge. Polanski’s September 2026 announcement that he will seek the Green nomination for the Holborn and St Pancras by-election, backed by local members, ties his position to upcoming electoral performance. Leadership elections occur every two years, with the next cycle expected in 2027 absent an earlier contest or resignation.