Hundreds of economists are urging world leaders to end the era of tax havens, arguing they only benefit rich individuals and multinational corporations and serve to increase inequality.

The 300 economists, in a letter coordinated by activist group Oxfam, say poorer countries are hit hardest by tax dodging. The signatories , including Jeffrey Sachs of Columbia University's Earth Institute, argue there is no economic justification for tax havens and urge leaders to "lift the veil of secrecy" surrounding them.

The letter released Monday comes days before an anti-corruption summit in London, featuring politicians from 40 countries as well as representatives from the World Bank and IMF.

Many of the companies that featured in the leak of the so-called Panama Papers were incorporated in British Overseas Territories and the British Virgin Islands.