By revealing that senior officials overruled national security warnings to clear Peter Mandelson, this investigation reshaped the national debate on executive oversight and civil service integrity following his dismissal over links to Jeffrey Epstein.
Details of Peter Mandelson’s vetting process were a national security secret. No file produced by the government’s vetting agency, UK Security Vetting, had ever before been made public. This posed a problem for senior Government officials tasked with complying with a ‘humble address’ from Parliament, passed in February 2026, compelling the release of “all papers” relating to Mandelson’s appointment. The motion stated that documents deemed prejudicial to international relations or national security should first be shared with Parliament’s Intelligence and Security Committee, but some in Government were reluctant even to do that.
Olly Robbins, the Foreign Office Permanent Secretary who, it would later emerge, decided to grant Mandelson developed vetting clearance against UKSV’s advice, argued against disclosing the vetting documents to Parliament. He said they should remain in a “hermetically sealed box” for national security reasons. Others in government feared an attempted cover-up and warned that withholding such documents would amount to an extraordinary breach of Parliament’s wishes.
It was against this backdrop that Paul Lewis, Henry Dyer and Pippa Crerar began their investigation. The sensitivity of the subject matter made it an exceptionally difficult story to stand up. Only a small number of security officials and senior civil servants were aware of the contents of Mandelson’s summary vetting file; the Cabinet Office permanent secretary, Cat Little, would later tell Parliament she kept a list of those who had seen it. Even the Prime Minister was unaware of its contents. Yet Lewis, Dyer and Crerar were able to establish that UKSV had concluded, on 28 January 2025, that the overall risk posed by Mandelson’s appointment was “high” and had recommended “clearance denied”. They did so with the help of multiple confidential sources.
The impact was swift and far-reaching. Within hours of publication of the first story on 16 April, Starmer had dismissed Foreign Office permanent secretary Olly Robbins. The decision did little to stem pressure on the Prime Minister and his Government. Robbins, Little and Starmer’s former chief adviser, Morgan McSweeney, were all summoned to give evidence to the Foreign Affairs Select Committee. Starmer was repeatedly accused of misleading the public and Parliament over Mandelson’s appointment. It became the most consequential scandal of his premiership, severely damaging his authority.
Shortly after the Guardian’s first tranche of stories was published, the Government resolved to comply fully with the terms of the humble address. The ISC received a “flood” of previously withheld vetting-related documents, including Mandelson’s UKSV summary file. While the contents of that document have not been officially released, Lewis, Dyer and Crerar published the second part of their investigation on 27 May. It revealed that UKSV’s recommendation to deny clearance was based on concerns about Mandelson’s associations with senior figures in China, Russia and Israel, as well as an undeclared £1 million loan he received to invest in an Israeli start-up.
