Former street hustler at the heart of Livingstone's empire

The Lib-Dem mayoral candidate and former police commander, Brian Paddick, first came across Mr Jasper as a street hustler in Notting Hill. "Every year at carnival, his association would sell bits of the pavement they didn't own (to commercial stallholders)," said Mr Paddick. "Every year it would end up in a row between Lee and the local police chief, who would eventually give in and allow (traders) who had Lee Jasper licences, rather than local authority licences, through the police lines."

Born to a black father and white mother, who brought him up on her own, Mr Jasper was radicalised by his childhood in Seventies Oldham, a place he described as "imbued with a crude racism that would have been considered intolerable elsewhere". Moving south, he became a professional race campaigner, combining fiery scrap-the-Met rhetoric with a sideline in £500-a-day police racism awareness courses.

That balancing act came temporarily undone in 1995, when, after the death of a young black man in custody, Mr Jasper organised a protest outside Brixton police station which turned into a riot, causing several casualties and around £1 million in damage. In recent years, though, Mr Jasper has worked closely with the police and helped manage the cautious rapprochement that has taken place between black Londoners and the Met.

There is much praise for his role in the Lambeth police-community consultative group and in Operation Trident, the successful campaign against "black-on-black" shootings, where he leads the Met's lay advisory body.

Yet opinion about Mr Jasper remains very divided - both in Lambeth, where he still lives, and at City Hall. Although one of the top eight Mayoral advisers, he is intensely disliked by at least one more powerful colleague. In Brixton, said Mr Paddick, "he has been an influence for good in many ways, but many in the black community see him as being in it for what he can get out of it rather than for the community as a whole".

Mr Jasper played a major part in the Mayor's organising of a rival event to the Notting Hill Carnival, the Caribbean Showcase, held the same day but in Hyde Park. He had fierce clashes with carnival organisers, who accused him and the Mayor of trying to "take over" carnival and acting out grievances dating back to his failure to be appointed the carnival's director in 1989.

Mr Jasper is at the very heart of the Mayor's identity politics, in which Mr Livingstone's chosen representatives of different communities are wooed with favours and cash. He led the charge against Trevor Phillips, the equality chief who pronounced multiculturalism dead. And he has been very close indeed to the Mayor, though the distance between them is thought to have increased recently.

He supported the Mayor's staunch defence of Sir Ian Blair and defended the police on two issues which still anger many black Londoners - stop-and-search, where they are around four times more likely to be targeted than whites, and the controversial police DNA database, which will soon encompass around three-quarters of young black men.

But it is the behaviour of some in his circle that may damage Mr Jasper. The Standard has heard vitriolic criticism in Brixton - albeit all off the record. Politically active people there are still reluctant to air grievances in front of what they see as a hostile media and white establishment, and are worried the black community will be stereotyped as infighting. But there are now signs of a loss of patience by some in his circle.