The coalition of charities hopes to increase pressure on the G8 to deliver on pledges made two years ago.
In addition to the original aims of the Make Poverty History campaign, which called for debt cancellation, more and better aid and trade justice, the coalition is calling for "healthcare, education, water and sanitation for all". It also wants firm plans to prevent climate change.
Patrick Watt, policy officer at ActionAid, a member of the coalition, said: "The millions who got involved in the Make Poverty History campaign in 2005 won major commitments from the world's richest countries, but it means nothing without action."
There are plans for a mass demonstration on 2 June, when campaigners will join up along the Thames. The campaign will ask the public to register their support on a new website: www.yourvoice againstpoverty.org.uk.