Voting opens in high-stakes Holborn and St Pancras byelection

<p>Zack Polanski has led energetic campaign for the Greens, while Labour will hope to hold on to Starmer’s old seat</p><p>Voting has opened in the Holborn and St Pancras byelection, a contest seen as a key gauge of Andy Burnham’s ability to energise voters and whether Zack Polanski