3 resultsfor “Morgan McSweeney response to journalists' investigation”
Morgan McSweeney then resigning as Starmer’s chief of staff, saying he took full responsibility for advising Starmer to appoint Mandelson. In March, document released to parliament stated that national security adviser, Jonathan Powell
Morgan McSweeney [quit](https://www.theguardian.com/politics/2026/feb/08/morgan-mcsweeney-resigns-as-keir-starmer-chief-of-staff) as chief of staff amid anger over the appointment of [Peter Mandelson as US ambassador](https://www.theguardian.com/politics/2026/feb/08/peter-mandelson-should-hand-back-us-ambassador-payout-says-cabinet-minister). His position had grown increasingly untenable after the release of emails
investigation by the Guardian can reveal. According to multiple sources, Mandelson was initially denied clearance in late January 2025 after a developed vetting process, a highly confidential background check by security officials. Keir Starmer