Charities' warning over philanthropy tax George Osborne is planning to cap the maximum amount of tax relief that individuals can claim when donating to charity, along with a wide array of other tax perks which it is feared are being exploited. He has said he wishes to bring Britain in line with America, where the tax benefits for donations are also limited. However, David Bull, executive director of Unicef UK, said: "Put simply, this new legislation will have the unintended consequence of discouraging donations to charity by philanthropists, leaving some of the world's most vulnerable children as the real losers." Charles Saumarez Smith, chief executive of the Royal Academy of Arts, said: "At a time when it is stated government policy to encourage more philanthropy for the arts, it is completely ridiculous to provide limits to the amounts that are given." Ciaran Devane, the chief executive of Macmillan Cancer Support, said limiting tax relief could undermine attempts to fund its new London cancer centre which opened last week. "I say this more in sorrow than in anger, this is a mistake," he said. It should be fixed, and fixed quickly. Ministers have said that they want to work with charities to ensure that genuine philanthropy is not undermined by the new tax rules - indicating that the scheme could be watered down. American laws allow the limits to be "rolled up" and several years" tax affairs taken into account - a scheme which is now expected to be considered in this country.