Sector leaders have told the Prime Minister there should be a World Social Bank funded by abolishing offshore tax havens.
Their letter, sent in advance of this week's G20 summit, appeals to Gordon Brown and other world leaders to "reform international finance in a way that provides a real boost to the growth of the third sector".
Stephen Bubb, chief executive of Acevo, John Low, chief executive of the Charities Aid Foundation, Jonathan Lewis, chief executive of Futurebuilders, and Filippo Addarii, director of European chief executives body Euclid Network, say in the letter that about £255bn is lost each year to tax havens. Brown has already pledged to move against them.
The proposed World Social Bank could stimulate social investment, the group says, by developing the infrastructure for an international social investment market, working with private investors to grow this market and encouraging collaboration between different countries.
The letter urges G20 leaders to place civil society high on the summit agenda.