At the wedding venue in Gorton and Denton the Green Party chose for the news conference to mark a seismic by-election victory on national television, it was clear that Zack Polanski and his team were new to all of this. There was a sea of empty chairs and but a smattering of supporters in a huge, near-deserted room. Seasoned operators - be it Nigel Farage, Sir Keir Starmer or Ed Davey - would have had the placards lifted and the activists cheering, but Polanski and his new MP, Hannah Spencer,