The big problem with the Anti-Corruption Summit organised by British Prime Minister David Cameron on 12 May was that no one could agree on what it was for. It invited Nigeria's Muhammadu Buhari, Colombia's Juan Manuel Santos Calderón and Afghanistan's Ashraf Ghani Ahmadzai, as well as United States' Secretary of State John Kerry, but not the leaders of Ghana, Kenya, South Africa, Brazil or China, who all preside over chronic corruption problems.

Cameron's critics accused him of trying to divert attention from the embarrassing revelations that his family had benefited from offshore banking arranged by Mossack Fonseca, the Panama law firm whose computer files have been hacked and distributed to sundry journalists. In fact, Cameron's conference was planned long before the Panama Papers were published in April but the revelations have reinforced demands for more surveillance and tougher regulation. As Transparency International said at a conference organised by the Commonwealth on 11 May, with tax havens based in its overseas territories and crown dependencies, Britain is widely seen as providing a warehouse for corrupt assets.

Next month, Britain is to become the first major economy to make public the beneficial owners of companies registered in its territories but the list will not include all the secrecy jurisdictions and dependencies, such as the Isle of Man, Jersey and Guernsey, let alone the British Virgin Islands.