Christian Aid insists the 160 billion US dollars in tax revenue lost worldwide every year means poorer countries are losing out.

If the money was paid and allocated according to current spending patterns, the lives of 350,000 children under five could be saved every year.

The charity accused multi-national corporations of "routinely" paying as little tax as possible to the governments of developing countries.

Director Dr Daleep Mukarji said: "The abuse is so widespread and damaging that it is tantamount to a new slavery. The rich are getting richer on the backs of some of the most impoverished and vulnerable communities in the world."

Christian Aid has blamed tax havens for failing to tackle legal and illegal tax dodging, and accuses major accountancy firms of encouraging clients to take advantage of the lax regimes. Nearly half the world's tax havens are UK territories, Crown dependencies or part of the Commonwealth.