A Cabinet Office report, referencing media and general reputational concerns, highlighted Mandelson's previous resignations and his association with Epstein.
Lord Mandelson was sacked a day after the Prime Minister publicly expressed confidence in him, following the emergence of emails where Mandelson told Epstein to "fight for early release" and expressed admiration.
Cabinet Secretary Sir Chris Wormald stated that the information leading to Mandelson's withdrawal was not available during the initial due diligence process, despite Epstein connections being flagged.
The Cabinet Office has since improved its due diligence procedures and is considering a request from MPs to release further details from the report provided to the Prime Minister.