PM says it is ‘staggering’ and ‘unforgivable’ that he was not told Mandelson had failed security vetting. Lucy Hough speaks to the Guardian’s head of investigations, Paul Lewis

A decision to go against the recommendation of the vetting agency was taken by officials in the Foreign Office, spokesperson says.

PM faces calls to resign as government says he was ‘not aware’ Foreign Office overruled disgraced Labour peer’s vetting ‘until this week’