Plans include a power plant run on cow dung and another on tonnes of collected plastic rubbish ...

"We are the spiritual capital of India, this place is known as king of the pilgrims, of course we should be a smart city," Swami Anand Giri said at a crowded Hindu temple overlooking the holy river, as devotees filed in to touch his feet and receive his blessing.

On the couch in his office, Allahabad’s municipal commissioner or chief executive, Devendra Kumar Pandey, threw down a folder with pages of ideas proposed so far, including many from several Indian companies keen to get involved.

Along with the alternative power plants are proposals for optical fibre rollout to create wifi hotspots, door-to-door garbage collection with bigger machinery and manpower to stop dumping in public areas.

Then there’s a possible new airport for the city which sees only a handful of commercial flights every week and vies for space with the air force.

“We are at the planning stage, not the project stage,” Mr Pandey said. “We will try our best and hope for the best.”