Yesterday, though, the minister without portfolio admitted that he had not always been quite so "on message" as he is now. In the days long before he became Tony Blair's most loyal aide, even he had a short period of youthful rebellion.
Mr Mandelson told a group of council estate residents about an episode when, as a sixth former in north London, he "occupied" a disused council building with friends and turned it into a youth club.
The council tried to evict the young squatters, claiming the building was dangerous, Mr Mandelson recalled.
"It was derelict, but we just took the doors down and went straight in, as we had been told that we would have to move out of our previous building," the minister said.
"And once we had finished renovating it, I am pleased to say that Camden council did not have the face to turn us out," he said.
He was speaking after local residents had shown him round a King's Cross estate which has been the focus of a pounds 46m regeneration scheme. The building is now called the Winchester Centre and is still used by local community groups.
He said: "I am pleased to see the radical spirit is still alive."
The minister's tour of the estate was his first stop on a nationwide fact-finding tour of Britain's inner cities, which he has undertaken as part of his role as leader of the Government's social exclusion unit.
Mr Mandelson was full of praise for the "stakeholder" approach taken by residents and Camden council to the project.
- Fran Abrams,
Political CorrespondentReuse content