Christian Aid calls for a stop to two-tier tax systems
UK Crown Dependencies and Overseas Territories need to prevent two-tier tax systems, says Christian Aid's senior economic justice advisor.
Joseph Stead said more tax information exchange agreements (TIEAs) needed to be made with developing countries.
He said poor countries without access to TIEAs were at a disadvantage and could not recoup lost tax revenue.
But Guernsey's Chief Minister said it was already policy to negotiate TIEAs with any jurisdiction.
Deputy Peter Harwood said: "I met with Christian Aid's chief executive on Saturday at the G8 Open for Growth meeting, and she acknowledged the work Guernsey had done with developing countries.
"In fact the report they published that day showed that Guernsey had signed more TIEAs with developing countries than other Crown Dependencies or British Overseas Territories.
"Of course there is more for all jurisdictions to do - but Guernsey does not take a two-tier view of tax transparency."Level playing field
But Mr Stead said: "It is great to see that progress is being made... but what we really need is to make sure developing countries are going to benefit from these deals."
He said there needed to be a clear commitment to ensure developing countries are included so they can get the information they need for a level playing field.
On Saturday representatives from Bermuda, the British Virgin Islands, the Cayman Islands, Gibraltar, Anguilla, Montserrat, the Turks and Caicos Islands, Jersey, Guernsey and the Isle of Man were at a meeting at 10 Downing Street.
They have agreed to sign up to the Multilateral Convention on Mutual Assistance in Tax Matters - an initiative led by the Organisation for Economic Cooperation and Development (OECD).