Zack Polanski has led the Green Party of England and Wales since September 2025, overseeing membership growth to over 230,000, local election gains, and the party’s first parliamentary by-election win. Recent months brought scrutiny over an impermissible donation, council tax questions on his residence, CV claims, and internal handling of anti-Semitism concerns alongside member motions on policy shifts such as Zionism. Party approval ratings have declined amid a Labour rebound under Prime Minister Andy Burnham, prompting some internal warnings of stagnation risks. Polanski’s announcement to seek the Holborn and St Pancras by-election seat, with local selection expected shortly, positions him centrally in upcoming contests that could shape leadership stability. Trader consensus reflects these competing dynamics of expansion versus emerging factional and polling pressures.