The notoriously outspoken Livingstone seldom apologises for anything, but he choked up as he read an account of the brutal tortures suffered by slaves in Britain's Caribbean colonies.
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Livingstone broke down in tears as he apologised for his London's role in the transatlantic slave trade
And the politician once nicknamed 'Red Ken' for his left-leaning views angrily denounced the role of his city's corporations in financing the trade.
"You can look across there to see the institutions that still have the benefit of the wealth they created out of slavery," Livingstone said, pointing through a huge window at the skyscrapers cluttering London's financial district.
"As mayor, I offer an apology on behalf of London and its institutions for their role in the transatlantic slave trade."
US civil rights campaigner the Reverend Jesse Jackson praised the statement, saying Livingstone broke important ground with his remarks.
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Moved to tears: Livingstone's eyes well up before he finally has to wipe them
Jackson said apologies should lead to reparations.
Livingstone did not explicitly mention restitution, but his tearful expression of remorse went further than then-Prime Minister Tony Blair's statement on the 200th anniversary of the law that ended the slave trade in March.
Blair expressed his deep sorrow, but did not make a direct apology.
Livingstone said London would mark the horrors of slavery with an annual memorial day timed to coincide with the UN's International Day for the Remembrance of the Slave Trade and its Abolition, held every August 23.
London played a central role in the slave trade, outfitting, financing and insuring many of the ships that ferried living cargo to plantations in the New World. Revenue from the trade helped fund the construction of London's docks.
London is not the first to apologise for the trade. Liverpool, one of the great European slave-trading ports, formally apologised in 1999.
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Ken Livingstone is obviously hoping to gain votes in London with his crocodile tears. He should be saving his sorrow for the passing of Britain as we once knew it.
- Pat Sweeney, Lanark
I never thought I'd say these words, but thank you Ken.
Thank you for giving me the biggest laugh I've had in months with your pathetic, apologetic, crocodile tears.
- L, London
Long lunch, was it?
- William Owen, Cardiff , Wales.
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