When Britain’s adopted steel king Lakshmi Mittal, gala-favourite philanthropist and one of the country’s most visible billionaire residents, quietly announced he was shifting his tax residency to Switzerland, it barely caused a ripple in Westminster. Another wealthy non-dom heading for more forgiving fiscal pastures, shrugged the commentariat. But for anyone paying attention to Britain’s charitable sector, Mittal’s departure is more than a footnote in a tax-policy debate. It is a red flag. A warning. A...










