Tony Blair's appointment as Middle East envoy has elicited doubts from many quarters, including parts of the peace Quartet - the European Union, the United Nations, Russia and the US - which he will be representing.

Some international players in Middle East diplomacy fear the high profile of the former UK prime minister will overshadow their own involvement. Others say his limited mandate, focused on Palestinian economic development and governance issues, prevents substantive progress on the Palestinian-Israeli conflict.