Starmer was left in dark about Mandelson’s vetting by two other top civil servants

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

Keir Starmer was left in the dark about sensitive information relating to Peter Mandelson's security vetting by two other top civil servants, including the head of the civil service, the Guardian can reveal.

The prime minister said on Friday that it was unforgivable" and staggering" that senior officials did not tell him that Mandelson failed a security vetting process weeks before he took up his role as ambassador to Washington.