Who is Peter Mandelson and what do we know about his relationship with Jeffrey Epstein?

Labour veteran Lord Peter Mandelson is facing his biggest controversy to date over his relationship with paedophile sex trafficker Jeffrey Epstein.

A message from the UK ambassador to Washington featured in a "birthday book" for Epstein for his 50th birthday in 2003 - three years before allegations against the disgraced financier became public. But who is Lord Mandelson, what did he put in his message to Epstein, and what has he said about their relationship? 'The Prince of Darkness' Lord Mandelson, 71, holds what is considered the most glittering diplomatic post in the UK government, the perks of which include the luxurious ambassador's residence, a mansion designed by top architect Sir Edwin Lutyens.

Sir Keir Starmer said Lord Mandelson, who served in both Tony Blair and Gordon Brown's governments, brought "unrivalled experience to the role" and has since credited him with helping build UK-US relations in a tricky political climate with Donald Trump at the helm. Lord Mandelson was already notorious among the British public, having earned himself a reputation for being a spin doctor when he helped propel Mr Blair to leader of the Labour Party in 1994, in what was seen as a betrayal by his close ally Mr Brown.

He was largely seen as the mastermind behind the birth of New Labour, and would berate newspaper editors when unfavourable stories were written by their political journalists, eventually earning him the nickname "the Prince of Darkness". He had to resign from Mr Blair's cabinet twice, first over an undeclared bank loan and then over intervening in a passport application by a top Indian businessman.

Yet it was Mr Brown who gave him a spectacular political comeback, making him business secretary with a peerage in 2008 before making him first secretary of state a year later - a role he kept until Labour's election defeat in 2010. Lord Mandelson, who was also Brussels commissioner from 2004 to 2008, is credited by supporters with having top trade experience and networking abilities, and has even been endorsed by UK Reform leader Nigel Farage, who has called him a "very clever man".

What was in Mandelson's birthday message to Epstein? Files from the 2003 birthday book compiled for Epstein by his co-conspirator Ghislaine Maxwell show a birthday note from Lord Mandelson, who refers to Epstein as "my best pal". It begins with him appearing to reminisce about the first time he met Epstein, before alluding to how the financier would often leave one alone with some "interesting friends to entertain".

It is not clear what was meant by these so-called "interesting friends.