The Greens have dropped to just nine percentage points in one devastating poll days after losing a crunch by-election and facing major backlash over a controversial party conference.An Opinium survey for the Observer put the left-wing party on their lowest share of the vote since Zack Polanski was elected as Green leader a year ago.AdvertisementIt’s a steep decline compared to where the party were during the May local elections, when Opinium put the Greens on 16 points.Support among young people, aged 18-34, has particularly waned, dropping from 28% to 14% in just five months.The poll also found Polanski was the...