As churches across the country finalise preparations for the 200th anniversary of the abolition of the slave trade on Sunday, the Mayor of London, Ken Livingstone, has formally apologised for the capital's role in the slave trade.

He went on to urge Prime Minister Tony Blair to follow suit by issuing an official apology on behalf of the UK, reports the BBC.

"The Government's refusal of such an apology is squalid," Mr Livingstone said, reigniting the debate on the Government's stance.

He urged fellow Londoners to join him in apologising for this "monstrous crime".

Mr Livingstone pointed to formal apologies issued already by France, the US state of Virginia, the city of Liverpool, and the Church of England.

"It will be infinitely better for our country's reputation if that apology is made now justly, frankly and openly," he said, and added: "Delay demeans our country."

Rev Rose Hudson-Wilkin, chair of the national Committee for Minority Ethnic Anglican Concerns in the Church of England, told Christian Today, "If it [an apology] doesn't come I won't be upset or alarmed. It needs to come voluntarily. One should not be press-ganged into saying it.

"If somebody has to beg and plead with you to do it then forget it, don't bother doing it, because it becomes meaningless then."

Mr Blair has previously expressed "deep sorrow" for Britain's role in the slave trade but has so far stopped short of issuing a full apology.

In an article for the New Nation newspaper in November 2006, Mr Blair said it had been "profoundly shameful".

Simon Woolley, the director of Operation Black Vote, said the mayor had made a "bold but undeniable statement".

"By apologising, we begin the process of reconciliation and addressing the legacy of this gross act of inhumanity," he said.

"It is important because the legacy of slavery remains with many black people on a daily basis."

The Bicentenary of the Abolition of Slavery Act, which banned slavery throughout the British Empire, is on Sunday 25 March.