London mayor Boris Johnson (pictured right, Reuters) is facing further questions on Metropolitan Police use of the Regulation of Investigatory Powers Act on journalists.

In his role as head of the Mayor's Office for Policing and Crime, the Conservative is charged with ensuring accountability of the Met – which has admitted using RIPA to secretly grab the phone records of The Sun as part of its Plebgate leak investigation.

Johnson, former editor of The Spectator magazine, at first defended police use of RIPA to obtain Sun phone records before admitting he hadn’t studied the case “in great detail” and then performed a U-turn when speaking at a press ball.