Green Party leader Zack Polanski has described the climate crisis as the greatest threat facing Britain since the Second World War, making the claim during an appearance alongside BBC naturalist Chris Packham. The comments come as Polanski continues to position climate action as central to his leadership of the Greens, while Packham has separately drawn attention for saying he "fantasises" about climate change denial being made a criminal offence.

The pairing of the two figures has fuelled debate over the tone of climate campaigning in Britain, with critics likely to seize on Packham's remarks about criminalising denial as evidence of intolerance towards dissenting views, while supporters may see it as reflecting the urgency both men attach to the issue. Polanski, who leads the Green Party, has increasingly used high-profile media appearances to press the case for radical climate policy, framing the crisis in historic terms comparable to wartime emergency.