Achieving consensus on the G20 leaders' declaration will be tough, the British envoy to India told broadcaster CNBC-TV18 on Monday ahead of a G20 summit in New Delhi on Sept. 9-10.

Alex Ellis also said Britain supported India's proposal to allow more countries to join the G20, following Prime Minister Narendra Modi's push to make the African Union a permanent member of the bloc.

(Reporting by Shivam Patel in New Delhi; Editing by Alex Richardson)