Brit Marling as Liz Garvey, Director of Communications James Nesbitt as Sir Richard Miller, Commissioner Bertie Carvel as Finn Kirkwood, Communications Deputy Ella Smith as Mia Conroy, Communications staff member Paterson Joseph as Charles Inglis, Assistant Commissioner, later Commissioner Jonny Sweet as Tom Oliver, Superintendent and Personal Aide to the Commissioner Nicola Walker as Sharon Franklin, Assistant Commissioner Jill Halfpenny as PC Davina Bancroft, TSG officer, married to SCO19 officer Banjo Cavan Clerkin as PC Damien "Clarkey" Clarke, TSG officer Owain Arthur as PC Paul "Nobbo" Norrington, TSG officer Adam Deacon as PC Robbie Vas, TSG officer who moves over to SCO19 Andrew Brooke as PC Neil "Banjo" Bancroft, SCO19 officer, married to TSG officer Davina Stuart Martin as PC Tony Forbes, SCO19 officer Nick Blood as PC Warwick Collister, SCO19 officer Daniel Kaluuya as Matt Coward, documentary film maker Ralph Brown as Grant Delgado, Deputy Mayor of London