Fairtrade and Comic Relief are targeting pupils across the UK in a joint campaign to push their Dubble chocolate bar.
Chocolate lovers can sign up through a web site, www.dubble.co.uk, to become "Dubble Agents". They receive an "Agent for Fairtrade" pack containing a range of materials, including a membership card, badge and series of missions for the coming year.
Activities include asking school tuck shops to stock Dubble chocolate bars, writing reports for local newspapers and liaising with other Dubble Agents in the UK.
More than 8,000 schools have already signed up to promote the chocolate bar to their pupils; teacher support material is available on the web site.
Kika Dixon, brand manager at Dubble, said: "Dubble offers an ideal starting point for young people to learn about global issues in an accessible and fun way and then take practical action to initiate change."
Dubble was launched by Fairtrade and Comic Relief to raise funds for cocoa farmers in Ghana.