Moments of quiet reflection will punctuate the procession as African drummers beat a sombre lament. The march will culminate in a symbolic “release from the past”, possibly in the form of a replica slave auction notice being torn up or shackles being removed from the cross.

The “walk of witness” on March 24 coincides with the bicentenary of the abolition of the slave trade. It is the latest stage in the church’s repentance since February last year, when the General Synod voted to apologise for its involvement in slavery.

Displays of remorse have been spearheaded by politicians. Just two months ago Tony Blair expressed his “deep sorrow” for Britain’s role in the transatlantic slave trade, although he stopped short of a full apology.

John Prescott, the deputy prime minister, is leading the national commemorations. Organisations including English Heritage and the National Trust have joined in, expressing regret that some of the properties they own were built with slave money.

According to draft plans, churches across Britain are being encouraged to bus up to 8,000 parishioners to London for the “act of public witness”.

Rowan Williams, the Archbishop of Canterbury, and John Sentamu, the Archbishop of York, who grew up in Uganda and has described how his forebears were among those enslaved, hope the event will signal the “beginning of a healing process”.

This weekend one of the march’s organisers denied the church was indulging in “hand-wringing” and compared the slave trade to the Holocaust.

“We are still living with the legacy of slavery,” said Rose Hudson-Wilkin, chairwoman of the church’s Committee for Minority Ethnic Anglican Concerns. “Black people are saying, ‘Hey, we had our own Holocaust, too. We had millions killed and we want this acknowledged’.”

Critics, however, believe that laying all the blame for slavery on Europeans is misleading. Arabs traded slaves from a much earlier date, while African kings and merchants were responsible for capturing their kinsmen and selling them to traders in exchange for goods and firearms.

The march will take two separate routes through the capital, meeting at Kennington Park in south London for an open-air church service. Williams and Sentamu are expected to march alongside a group of black and white youths bearing the cross.

Before leaving Whitehall, the archbishops will take part in an act of reflection. They will then walk past the Houses of Parliament, pause for remembrance prayers at Victoria Tower Gardens, and proceed to Lambeth Bridge. From this point, the marchers will fall silent — except for the African drummers and a small group of singers.

The route across the Thames has been chosen to represent the Atlantic crossing made by more than 10m Africans sent to the Americas between the 15th and early 19th centuries.

The climax of the service is likely to be the symbolic “release from the past”, followed by a “song of freedom”. Worshippers will be asked to sign a petition calling on the government to take action against modern-day slavery, such as sex trafficking from eastern Europe.

Last year’s synod was told how the church’s missionary arm, the Society for the Propagation of the Faith in Foreign Parts, owned the Codrington plantation in Barbados where slaves had the word “society” branded on their chests.

50 rescued child slaves vanish

FIFTY children who were trafficked into Britain to work as slaves have gone missing from social services supervision.

A report on the trade in children will this week reveal that two out of three victims safeguarded by local authorities in Manchester, Newcastle and Birmingham have vanished.

Social services in the three cities have identified 80 children from Africa, China, south Asia and eastern Europe who were trafficked to work as prostitutes, domestic servants and cannabis “farmers”.

Two boys disappeared from social services offices in Birmingham and Manchester. Others vanished from emergency housing, foster care and a home that had guaranteed 24-hour surveillance.

The report by Ecpat UK, a coalition of charities including Save the Children, calls for a national inquiry into separated children who go missing from care. 50 rescued child slaves vanish

Click here for more on the achbishops' slavery march: www.makingourmark.org.uk

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