Thousands of documents related to Lord Peter Mandelson’s appointment and activities as ambassador to the US will be published on Monday afternoon, Downing Street has said.
The Prime Minister’s official spokesman said the publication of the files, the second tranche relating to Sir Keir Starmer’s decision to give the prestigious Washington job to Lord Mandelson rather than a career diplomat, would be an “unprecedented piece of Government transparency”.
The whole of Government effort to uncover files relating to the posting is expected to include declassified documents as well as information of a party political nature, No 10 said.
Ministers are braced for further embarrassment over revelations in the files, which are reportedly set to include thousands of WhatsApp messages likely to contain the private views of senior Government figures.
Speaking on Monday ahead of the publication, the Prime Minister’s official spokesman said: “This is a task that has involved every Government department.
“The result is the largest-ever Government response to a humble address. It represents thousands of hours of work from officials across the Government to deliver an unprecedented piece of Government transparency.
“Our guiding principle throughout has been to comply as transparently and as swiftly as possible.”
He added: “For example, material of a party political nature will be included in the publication, which is contrary to usual practice and precedent, in order to demonstrate the maximum possible transparency.
“A number of documents have also been declassified to enable publication.
“In order to provide transparency to Parliament and the public alongside the documents, we will also provide a clear explanation of the steps taken in this official-led process to gather the documents and the approach to any redactions.”
No 10 indicated the release of documents was everything it planned to publish on Lord Mandelson, apart from files held back at the request of the Metropolitan Police.
Among the documents the police force asked the Government to withhold is Lord Mandelson’s UK Security Vetting (UKSV) summary, in order to avoid jeopardising its investigation into alleged misconduct in public office by the peer.
MPs voted in February to demand ministers publish a wide range of documents relating to the appointment using an archaic parliamentary procedure known as a “humble address”.
The vote followed the launch of a police investigation into Lord Mandelson and concerns about the vetting process involved in his appointment.
A first tranche of documents, released in March, showed Sir Keir was warned of a “general reputational risk” because of Lord Mandelson’s connection to the late paedophile financier Jeffrey Epstein.
The second set of documents is expected to include messages between Lord Mandelson and ministers and Government advisers, including Sir Keir’s former chief of staff Morgan McSweeney.
Former health secretary Wes Streeting has already published his own messages with Lord Mandelson, including discussion over Gaza and criticisms of Sir Keir’s leadership.
Files unlikely to be released on Monday include UKSV’s recommendation against granting Lord Mandelson security clearance.
Top Foreign Office official Sir Olly Robbins overruled that advice, and was effectively sacked in April, with the Prime Minister insisting he was unaware of UKSV’s recommendation.
Several documents have also been redacted, either to remove personal details such as the names of junior officials, or on national security grounds.
Redactions on national security grounds were agreed with Parliament’s Intelligence and Security Committee following a compromise with MPs to head off a backbench rebellion on the demand for documents.
Last month, the committee raised concerns that the Government was applying redactions “too broadly”, and cited the UKSV vetting file as an example of documents being withheld without Parliament granting ministers the “authority” to do so.
