Key Points:

Nelson Mandela has boycotted plans to commemorate the bicentennial of the Act abolishing the slave trade in Bristol after hearing of bitter divisions within the community and accusations of racism and intolerance.

Mr Mandela had been invited to Bristol, once one of the busiest slave ports in Britain, by the Lord Mayor, councillor Peter Abraham, for a service of remembrance due to take place today.

But South Africa's former president declined the invitation after local black organisations contacted him to say his presence would be seen as condoning an overwhelmingly white city council which is accused of riding roughshod over the wishes of the city's black population.

The Consortium of Black Groups, which sent the message, plans to hold demonstrations outside the service. Spokeswoman Hilary Banks said: "We pointed out to Mr Mandela that Bristol is not quite the liberal, multi-racial place it pretends to be.

We said that if you do come to Bristol, we'd like your visit to change the position of the black people in the city. We did not tell him not to come; that was obviously his own decision.

"We are going to hold a protest at the service because the venue is wrong for something like this. The church in Bristol had traditionally justified slavery and benefited from it." St Mary's Radcliffe is one of the landmarks of the city.

Pointing at the spire, Ms Banks continued: "Slaves were kept in dungeons under the church and there were tunnels to the dockside. That is how the church used to treat slaves."Another famous landmark is Colston Hall, named after Edward Colston, a merchant who made his money out of slavery.

The Bristol band Massive Attack has always refused to play there. Black groups say a fitting way for the city to acknowledge a part of its shameful history would be to change the name, which the council has refused to do.

The "name blame", as it has become known, is a symptom of deep resentments. Despite 8 per cent of the city's population being from ethnic minorities, the 70-strong council has only two non-white councillors.

"But there is also a lot of anger and dissatisfaction among the white working class, and this row has brought some pretty ugly stuff to the surface," said Marvin Rees of the Black Development Association. "The level has degenerated to 'go back to Africa' standard. I don't think the council will change the name of Colston Hall; there are no votes in it."