Many children in developing countries do not attend school

The Global Campaign for Education expects hundreds to take part in the event on 23 April, the day before a World Bank meeting in Washington.

The organisation says $5.6bn (�3bn) is needed to ensure every child has the chance to attend school by 2015.

Governments have promised to supply adequate funding for projects.

'Costs less than ice cream'

Research shows children who miss out on an education are more likely to grow up poor and unhealthy, and that their own children are more likely to die as infants.

GCE spokesman Anne Jellema said: "Governments, including our own, have promised to provide the money needed to put all children in school by 2015 but these promises will be broken if they don't act now.

"More than 100 million children never see the inside of a school but it wouldn't take much to change this.

"Just $5.6bn from rich countries - half the amount that Europeans spend on ice cream each year - would help give every child in the world the chance of an education."

Some pupils will visit parliament to talk to ministers on 20 April.

The events, parts of a week of action, will be mirrored around the world.

Janet Taylor, a teacher from Millfields Community School in Hackney, east London, said: "This is a fantastic opportunity for the children to learn more about the power they have to change the world."

She added: ''This event will bring the lessons in citizenship to life and put an end to the idea that young people aren't interested in politics or the big issues of the day.

"The onus will then be on political leaders to demonstrate they are listening to their demands."