When the horrific transatlantic trade in human life was finally abolished in the early 19th century, anti-slavery campaigner William Wilberforce could never have imagined the scale of the modern day slavery problem that would grip the world 200 years later.

During the peak of the brutal trade in the late 18th century, some 80,000 Africans were torn from their families every year and shipped by Europeans to the Americas.

The terrible human cost is hard to quantify. But anti-slavery campaigners estimate that of about 24 million people who were enslaved in Africa, only some ten million survived long enough to reach the Americas and Caribbean.

Those who survived the crossing, amid atrocious conditions on-board cramped, disease-ridden ships, were then worked to death while forced to harvest cash-rich crops like rice, coffee, sugar and tobacco, in the Caribbean and southern and northern America.

Hull-based MP Wilberforce led the parliamentary campaign against the slave trade, which was abolished in 1807.

March 25, 2007, marks the bicentenary of the Slave Trade Act, which banned British participation in the Atlantic trade.

After mass protests and slave rebellions, an act was passed in 1833 abolishing slavery in the British colonies. That sequence of events may have ended a shameful chapter in human history that started more than three centuries earlier.

But, tragically, the evils of slavery still flourish today ? making the struggle as relevant now as it was in Wilberforce?s day. Despite the fact slavery is banned by the 1948 Universal Declaration of Human Rights, the United Nations says that there are now at least 12 million people living in slavery. That statistic is shocking.

And Archbishop Desmond Tutu spoke for many when he said in 1999: ?Slavery... I didn?t know about all these forms that existed. I think it?s largely because we aren?t expecting it. It is hidden.

?Generally people would not believe that it is possible under modern conditions. They would say: ?No, I think you are making it all up?. Because it?s just too incredible...?

Unfortunately the problem is far from made up.

There has been a resurgence in slavery the last half century, fuelled by discrimination, booming population levels in the developing world and grinding poverty that makes people vulnerable to discrimination in a cost-driven marketplace where there?s rising pressure to keep prices down.

From India to Brazil, from the Philippines to the UK, its tentacles stretch deep into four corners of the world.

People are sold like objects, forced to work for little or no pay and are at the mercy of so-called employers.

Women from Eastern Europe are bonded into prostitution, children are trafficked between West African countries while men are forced to work as slaves on Brazilian farms, in exploitation that affects people of all ages, both sexes and all races.

Today, a slave costs, on average, the equivalent of ?60. And because slaves are so cheap, they become disposable commodities, rather than people.

The types of slavery in existence today are varied, but some of the most widespread include:

n? The transport and/or trade of women, children and men for the purpose of forcing themselves into slavery conditions.

This is a global problem impacting every continent and most countries in the world.

It is estimated that as many as 800,000 people get trafficked across national borders annually, after being deceived or coerced into leaving their home or country to be exploited.

Most victims work in the sex industry, and it is estimated that 80 percent of the victims are female. The FBI says that human trafficking generates $6.5 billion a year and is closely linked to money laundering, document forgery and drug trafficking.

n? Some 8.4 million children across the globe are understood to be working in often dangerous conditions.

Many children are employed as domestic slaves in the Philippines, and they can be subject to physical, verbal and sexual violence.

In a recent campaign against child soldiers, Amnesty International reported that more than half a million children under-18 have been recruited into government armed forces, paramilitaries, civil militia and a wide variety of non-state armed groups in more than 85 countries.

Often abducted to join armies, many of these children ? some younger than ten ? have witnessed or taken part in acts of unbelievable violence, often against their own families or communities.

n? Affects people who are illegally recruited by individuals, governments or political parties and forced to work, usually under threats of violence or other penalties.

Thousands of men are trafficked into forced labour in Brazil. They have to work to pay off debts after being told they owe money for transport, shelter, food and equipment.

n? Affects millions of people worldwide. People become bonded labourers by taking or getting tricked into taking a loan. This can be for as little as the cost of medicine for a sick child. Repayment is through often arduous year-long work.Basic food and shelter is the ?payment? for this work, although debts may sometimes never be paid off and they can be passed down through generations. Most prevalent in India when somebody becomes bonded when his or her labour is demanded as repayment for a loan. Debts are often passed through generations of the same family.

n? Affects women and girls who are married without choice and forced into lives of service ? often accompanied by physical abuse.

n? When people are either born into a slave class or are from a group that society views as suited to being used as slave labour.

Tens of thousands of people in parts of West Africa are forced to work for no pay because of their social standing or ethnicity.