Exclusive: Opinions split on ‘unprecedented’ release of files, despite demand for ‘all papers’ related to ex-US ambassador’s appointment

Guardian investigation uncovers decision by UK security officials to deny clearance before Mandelson took up role as US ambassador

Ministers and civil servants face scrutiny after revelation Foreign Office overruled vetting procedure for US ambassador appointment

Exclusive: Opinions split on ‘unprecedented’ release of files, despite demand for ‘all papers’ related to ex-US ambassador’s appointment

Speculation over the prime minister’s future dominates UK front pages after the Guardian revealed Peter Mandelson failed his security vetting

The PM is facing calls to resign over the revelation that Lord Mandelson did not pass security checks.

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

Exclusive: Officials have spent weeks debating whether or not to release highly sensitive information about the affair

Almost all officials working in Foreign Office HQ undergo process before gaining access to top secret material

Inquiries into who knew what, and when, will be pored over in coming weeks and could ultimately decide Starmer’s fate

PM said he was ‘staggered’ not to have been told that Peter Mandelson had failed his security vetting before becoming ambassador to the US