Lord Peter Mandelson has been arrested on suspicion of misconduct in public office as part of an investigation by Metropolitan Police after allegations he passed on market-sensitive information to paedophile financier Jeffrey Epstein while serving as business secretary.
It is the latest development in the growing crisis engulfing the former US ambassador, who has resigned from the Labour Party and has left the House of Lords after further details of his friendship with the convicted felon emerged in the so-called Epstein files.
Sir Keir Starmer is under growing pressure after he admitted that he knew about Lord Mandelson’s ongoing friendship with the convicted sex offender when he appointed him, but said that the peer “lied repeatedly” about the extent of the relationship.
Downing Street then tried to control the release of potentially explosive documents, which provide insight into how the decision was made.
But in the face of a mutiny from Labour MPs – led by former deputy prime minister Angela Rayner – the government had to back down and cede control to Parliament’s Intelligence and Security Committee to decide what could be released into the public domain.
The prime minister’s acceptance followed the launch of a criminal probe into allegations Lord Mandelson passed information to Epstein while serving in Gordon Brown’s Labour administration as it dealt with the fallout from the 2008 financial crash.

Sir Keir faced a backlash from his own back benches, including his former deputy Ms Rayner, over an attempt to have some papers “prejudicial to UK national security or international relations” withheld.
Labour MP Andy McDonald said he thought it was “reasonable to expect an answer pretty damn quick” on how Lord Mandelson passed vetting.
“It beggars belief that we could ever get a security vetting process that would sign off affirmatively on somebody in these circumstances,” he said.
He said it was “an appalling failure of judgment” that Sir Keir appointed Lord Mandelson given what was already in the public domain about him.

In a statement confirming the arrest, the Met said: “Officers have arrested a 72-year-old man on suspicion of misconduct in public office.
“He was arrested at an address in Camden on Monday, 23 February and has been taken to a London police station for interview.
“This follows search warrants at two addresses in the Wiltshire and Camden areas.”
Lord Mandelson resigned from the Labour Party earlier this month, saying he wanted to avoid causing it “further embarrassment”, after losing his post as UK ambassador to the United States last year because of his links to Epstein.

Sir Keir Starmer rallied around his man in Washington for days at the time, praising the job the UK’s ambassador had done penetrating Donald Trump’s inner circles. But the prime minister was forced to change course last year, dismissing Lord Mandelson with immediate effect.
These developments mark what is almost certainly the end of a career that had previously been defined by remarkable comebacks. His mastery of political intrigue had earned him the nickname “Prince of Darkness”.
Last year, before heading to the US, Lord Mandelson was living in a luxurious farmhouse in the Pewsey Vale in Wiltshire. During the pandemic, he wrote about the “cosy country life” he was enjoying on the farm.
He is the part-owner of Global Counsel, a powerful lobbying firm he co-founded, but they have swiftly reassured clients that they are in advanced stages of divesting his remaining stake as it attempts to cut ties with the peer.

As well as the influential business position, Lord Mandelson has the more ceremonial High Steward of Hull title, though the council will try to strip him of it in the coming weeks.
But while he returns to a lavish life in Britain, it won’t be a touch on the grandeur of life in the early-1900s residence built for Britain’s ambassador in Washington, one of the most luxurious properties in the US capital.
It has previously welcomed royalty from Prince Charles and Princess Diana to pop royalty like The Beatles, while guests who have been hosted in the embassy since Lord Mandelson moved in include much of President Trump’s inner circle and the great and good of American business.
No Labour leader will bring the tarnished grandee back into the fold after the extent of his relations with Epstein were revealed. And he has said himself at one point that further “very embarrassing” information will come to light in the future.
His career has been one of many comebacks, but this latest criminal investigation and subsequent arrest seems a fall too far for Lord Mandelson to recover from.
Ukraine war latest: Putin has ‘not broken Ukrainian people’ as war enters fifth year
Starmer orders ethics chief to investigate minister over targeting of reporters
Mandelson arrest latest: Ex-peer released on bail as Virginia Giuffre’s family react
Reform will face down any ‘progressive outrage’ over mass deportations, Yusuf says
Who is Peter Mandelson and what do we know about his relationship with Epstein?
Starmer makes visit at Gorton and Denton by-election in bid to save his premiership