In the marriage of the three people at the heart of New Labour, he is the wounded party who has bravely kept his counsel until he could hide the truth no more, and he has now told his story in a lip-trembling interview in which real tears were never far away.
Peter Mandelson has travelled a long way in the 15 years since he fell out with Gordon Brown over the Labour succession. But the People's Prince of Darkness has improbably achieved the redemption denied the People's Princess.
"Gordon's difficulty in those days was not principally with me," Lord Mandelson recalled of the stormy period in 1994 when he backed Tony Blair's bid for the Labour leadership. "I was the third person in the marriage. I was the casualty."
The description, consciously paraphrasing the assessment of her own marriage by Diana, late Princess of Wales, brought some melodrama to an interview in The Times, in which Lord Mandelson recalls the difficulties of the three-way relationship at the top of the Blair government. The rifts are healed, but it is clear he believes that what he calls "the schism in the new Labour family" was as painful as the infidelities that wrecked the Princess of Wales's marriage.
He mimics the most memorable element of the princess's 1995 interview with Martin Bashir. "Has Brown apologised for his behaviour? Long pause. 'That must remain private between us.' As he talks of the reconciliation, Mandelson's eyes well up with tears, though none falls."Reuse content