The government's chief medical officer has warned that the new so-called tier three local lockdown restrictions, which are to be implemented in the most severe cases, will not work on their own.Just hours after Prime Minister Boris Johnson announced the new restrictions in the commons Professor Chris Whitty said he was not confident they would be enough to stop the spread of the disease.After being asked by BBC's Laura Kuenssburg: "Are you confident what's being announced can be enough to slow