For from dawn to dusk, thousands of black men will converge on the central London square for a day of prayer and spiritual bonding.
The 10,000 Man March is Britain's equivalent of the Million Man March, which took place in Washington DC three years ago. The event shocked the United States with its scale and intensity of feeling, prompting an exodus from some of the city's white suburbs amid unfounded fears of violence.
Organised by Louis Farrakhan, leader of the black Muslim Nation of Islam, the march inspired the Nation's British followers to attempt something similar.
How much support they can drum up is open to question. The build-up to the event has been low-key and has failed to attract the support of well-known black leaders and celebrities. While many blacks admire the Nation's discipline and smart image, it is thought to have fewer than 1,000 followers in Britain, mainly in London and Manchester.
The Nation has attempted to give the march a wider constituency by canvassing the support of other black groups, including some black Christian churches.
One of the march organisers - who have dubbed themselves the Black United Front, with the slogan "One God, One Aim, One Destiny" - even claimed to be a born-again Christian representing the African People's Revolutionary Party.
At a press conference this week, Michael Muhammad, the Nation's west London leader, promised that the event would be non-violent. "It is a time to reconcile our differences with those who have done us wrong and become friendly and peaceful again," he said.
Speaking beneath a picture of Mr Farrakhan, the Nation's British leaders said the rally was a time for "atonement" for the black man's failure to accept his responsibilities to his family and community and "our abuse and misuse of our women and girls". Mr Muhammad said that other races were welcome but "we are primarily calling out to the black man".
Jewish groups have asked the Metropolitan Police to monitor the rally for any evidence of anti-Semitism. Mr Farrakhan was banned from entering Britain after making a series of anti-Jewish statements.
Unlike the American march, today's rally, which starts at 5am, is unlikely to induce "white flight" among West End shoppers but it has the potential to become a significant moment in the history of British race relations.
The Stephen Lawrence inquiry, which was disrupted by Nation supporters, has forced the issue of racism into the national consciousness and rally organisers believe it will galvanise support for their event.
Mr Muhammad said: "We believe that Almighty God has put the Stephen Lawrence situation into the hearts of not just black people but ... all people who want justice in this United Kingdom."
The organisers say Trafalgar Square is a symbolic location because it celebrates the seapower that enabled Britain to generate wealth through the slave trade in the 18th century.Reuse content