Peter Mandelson, also called the Minister of Black Arts because of his prowess as a spin doctor, is to be shown on television in tears.
This public display of emotion, which may just help to melt some of the icy mistrust with which he is regarded by many fellow Labour Party members, comes in an interview in which he talks about the death of his father George.
Asked by clinical psychologist Oliver James if he can remember where he was when his father died, the Minister Without Portfolio nods, then pauses. As tears well in his eyes, he shakes his head and mumbles: "I can't go into that ..."
Visibly moved by the recollection of the death, Mr Mandelson is then asked: "Do you want to take a moment?"
The MP rubs his nose and replies: "I'm all right", before wiping tears away as the interview moves on to other subjects.
Mr James, who interviewed the MP for a new series called The Chair, which begins on BBC 2 next week, said he was "amazed" at the show of feeling from such a public figure.
He said: "The person who I was led to believe from the [newspaper] cuttings was the Prince of Darkness, a manipulator, was remarkably different from that. It is very unusual for somebody to be able to be in touch with their emotions yet also be the tough, hard person they have to be."
It was a positive sign for someone in his position to be aware of their background and their past, to "know where they are coming from", said Mr James.
Elsewhere in the 20-minute interview, due to be broadcast on 4 June, Mr Mandelson talks with evident pride of his Labour background and the fact that his maternal grandfather was the Labour minister Herbert Morrison. Early in his childhood he had "become my grandfather's grandson".
He talks movingly of his close bond with his mother Mary, who is still alive, and who was the "backbone" of the family, and of the "mutual admiration" he had with his father, even though he blamed his father's generation of Labour Party members for allowing in Militant Tendency, consigning the party to years in opposition.
The interview was conducted 18 months ago and its appearance now - in a series involving other public figures such as football manager George Graham and EastEnders actress Patsy Palmer - has come many months later than the MP expected.Reuse content