McSweeney to face MPs over Mandelson appointment and vetting row

Morgan McSweeney, Sir Keir Starmer’s former chief of staff, will face MPs next Tuesday over the appointment of Lord Mandelson, putting the internal workings of 10 Downing Street under scrutiny at a moment when the vetting row has become a test of standards at the top of government.

His appearance before the House of Commons Foreign Affairs Committee is highly unusual for a former prime ministerial chief of staff and will focus attention on how Mandelson was chosen as ambassador to Washington, what warnings were seen inside government, and whether normal safeguards were followed before the appointment was announced.

McSweeney resigned from Downing Street in February and publicly said he had advised Starmer to appoint Mandelson, taking responsibility for that advice. That makes him one of the central figures in a dispute that has moved far beyond a personnel row and into questions of transparency, patronage and accountability.

The controversy deepened after Sir Olly Robbins, the former Foreign Office permanent secretary who was sacked last week, told MPs he did not feel under pressure to wave through Mandelson’s security clearance, despite other reports that he had described a dismissive attitude and pressure from No 10. The Foreign Affairs Committee is now examining the appointment because it falls within its remit over Foreign Office work.

Starmer told Parliament on 20 April that he first learned on 14 April that Mandelson had been granted developed vetting clearance on 29 January 2025, against the specific recommendation of UK Security Vetting that it should be denied. He said that information had not been passed to him, the Foreign Secretary, the Deputy Prime Minister or the former Cabinet Secretary Sir Chris Wormald.

The prime minister said the appointment itself was made much earlier, after a Cabinet Office due-diligence process. Mandelson answered questions on 10 December 2024, final advice reached Starmer on 11 December, the decision was taken on 18 December and the appointment was announced on 20 December.

The row has also widened into a broader inquiry over who knew what and when. A November 2024 box note warned Starmer he could be more exposed if he made a political appointment, and there were repeated warnings about Mandelson’s links to Jeffrey Epstein. Starmer has since said he would not have appointed Mandelson if he had known of the vetting failure, and has now admitted he should not have appointed him.

The political fallout has intensified the pressure on Starmer, with Conservative leader Kemi Badenoch pressing him at Prime Minister’s Questions and forcing an emergency Commons debate. For the government, McSweeney’s testimony is likely to be more than a question of one appointment: it will be a measure of whether the machinery around the prime minister can still command trust when an appointment to Washington becomes a test of judgment in London.