Green leader Zack Polanski has called the decision ‘really grim’ Stay on top of the latest political news with our View from Westminster newsletter Get the latest political headlines with our free email Get the latest political headlines with our free email Email * SIGN UP I would like to be emailed about offers, events and updates from The Independent. Read our Privacy notice Two US left-wing commentators have been banned from entering the UK to speak at a conference this week, the Home Office