Children will protest outside Nestle Headquarters in Croydon today to stop the sale of "slave trade chocolate".

They will put pressure on the confectionary giant to label its products with a guarantee that they are not made using trafficked labour.

Children from Sir John Cass Primary School in the City of London, and The Hub youth group in Waterloo want to stop the forced labour of African children on cocoa plantations which provide raw material for a third of all UK Easter Eggs.

They will read testimonies from trafficked children and wear "For Sale" and "£20 only" signs - the price one boy was reputedly sold for by traffickers to work on a plantation, according to organisers Stop the Traffik.

The anti-trafficking campaign group said boys as young of 12 are taken from homes in Mali by deception or force by people traffickers and then sold to Ivory Coast plantations where they are made to work 12 hour days, seven days a week, in appalling conditions.

Nearly half the world's cocoa is harvested in the Ivory Coast.

In 2000, a US government Human Rights Report found more than 15,000 Malian children were trafficked into the area to work as slaves both on coffee and cocoa plantations - the majority on cocoa.

A Nestlé spokeswoman said: "Nestlé abhors human trafficking. We are working with our industry partners, other stakeholders and the UK trade organisation, the Biscuit, Cake, Chocolate and Confectionery Association (BCCCA) to ensure the cocoa we buy is grown without child and forced labour."Much of the UK's cocoa comes from Ghana and Cote d'Ivoire. In partnership with other chocolate companies, both in the UK and around the world, a diverse number of activities have been developed to tackle this issue."In addition, our industry association, the BCCCA has recently approached Stop The Traffik offering to update the organisation on the progress made. However, we are disappointed that Stop The Traffik has not taken up this opportunity, so far."