The march will cross five continents 90 countries

The organisers hope that over the next few months, millions of people will join the global march for at least part of its route.

The extraordinary protest will take five months to complete.A core group of Philippine protestors are to fly from Manila to Vietnam to cross Asia by land. They will continue into Europe and eventually arrive in Geneva.

There are 250m child workers around the world

There, the protestors will be joined by two contingents - one of which will have travelled across the Americas and the other, Africa.

Geneva has been chosen as the destination because the International Labour Organisation meets there in June to draft a new convention on child labour.

Shay Cullen, head of a non-government organisation working against sexual exploitation of children in the Philippines told reporters: "We want to stop the enslavement of children around the world."

"This is a generation of shame, the world should be ashamed that children are being used in this type of exploitation," he said.

Cullen said some 60,000 Filipino children were being exploited in the sex trade, 125,000 children in Thailand and 1.2m in India.

Indian campaigner, Kailash Satyarthi, who is leading the march, wants to draw attention to the estimated 250m child workers around the world.