Green Party leader Zack Polanski today claimed the 'climate crisis' is the biggest threat to Britain since the Second World War. Mr Polanski delivered his 'reality check' on 'extreme weather' at a press conference in Westminster, as he looked to bounce back from a series of scandals. Despite a surge in support when Mr Polanski first became leader, the Greens have since fallen away in opinion polls. The Green leader condemned Andy Burnham for not calling an emergency Cobra meeting in response to wildfires across Britain. Mr Packham also called for a 'transition to a plant-based diet', warning animal agriculture was a 'leading driver of biodiversity loss'.