A human rights activist announced on Monday that at least 12 million people, most of them children, are still trapped in slavery worldwide.
Children are forced into pornography and prostitution, and exploited as cheap labour and child soldiers, highlighted Sarah Williams of the pressure group Anti-Slavery International.
"They are more vulnerable, cheaper to hire and less likely to demand higher wages or better working conditions," she said of the 8.4 million children who are modern day slaves.
"This is unfinished business," she told a London seminar reviewing how multicultural Britain plans to mark the bicentenary next year of the abolition of its slave trade.
According to Williams, thousands of people have been abducted and enslaved in Sudan since the outbreak of civil war in 1983.
In addition, hundreds of thousands of people in Burma have been forced to work as farm labourers, army porters or construction workers for little or no pay.
Women are trafficked from countries like Albania and Moldova and forced into prostitution in France, Italy and Britain. Men are trafficked in Mexico and forced to work on US farms.
The child sold as a camel jockey, the woman forced into prostitution, the migrant worker whose passport is confiscated by his gangmaster boss; all in effect are slaves, she said.
In the run-up to the bicentenary, the British government has said it is contemplating whether to issue a "statement of regret", but no decision has yet been made on the emotive issue.
Liverpool, the northern port which transported about one million slaves from West Africa to the United States and the Caribbean, issued an apology in 1999.
Addressing the London seminar, Culture Minister David Lammy said: "The story of slavery is not over. We must all redouble our efforts to tackle injustice wherever we find it."
