Does Polanski have to go? Greens at the crossroads after Holborn and St Pancras

Pressure is building on Green Party leader Zack Polanski after a byelection defeat, a damaging row over Zionism, and polls that show him less popular than Nigel Farage. Polanski's leadership is being questioned after the party's loss in the Holborn and St Pancras byelection and a controversial tweet about Zionism.