The story of how Peter Mandelson failed his UK security vetting before he took up his post as ambassador to the US – and the overturning of the decision that he should not be given clearance – is full of the abbreviations of the British national security apparatus and the archaic language used to describe parliamentary process.
Here are the key terms to understand about the story, as Morgan McSweeney and Philip Barton answer questions from the foreign affairs select committee. McSweeney, formerly Keir Starmer’s chief of staff, and the ex-Foreign Office chief Barton are giving evidence about who knew what, when.
