It could be the most ambitious tourist development ever. Costa Navarino in Greece is a €1bn project with 11 new hotels, 3,000 rooms, six spas and no fewer than seven golf courses that is due to open next year. But the vast scale is less surprising than the resort's claim that the project, near Pylos in the Peloponnese, will be "the first 100% emission-free resort in the world".

The developer (costanavarino.com) set out its eco-credentials at the scheme's launch in London last week: from hiding solar panels in the mountainside to planted roofs reducing the need for air-conditioning.

Reservoirs have been created to contain excess water from local rivers in the winter months, said Costa Navarino's managing director, Achilles Constantakopoulos. His company has also applied for permits to create a tide farm to generate electricity. "Our aim is to produce twice as much power as we need - all from renewable sources," he added.

Can the resort achieve the seemingly impossible, by making a massive new development "green"? Environmental groups are torn between wanting to encourage "a new positive paradigm" for tourism development, while fearing a vast building project.

Nikos Charalambides of Greenpeace in Greece said it was concerned by the golf courses' use of water. "We are talking about a more-or-less intact area, so the project is literally 'planting' a whole village with all its infrastructure - even if the company manages to consume only green energy and agree on a binding zero waste policy.

"Last but not least, thousands of people are expected to move here, by plane, then car, thus increasing carbon emissions, to visit the 'first 100% emissions-free resort'."

"Genuine moves to slash emissions are welcome," said Andy Atkins of Friends of the Earth. "But you won't be having an eco-friendly holiday if you have to fly to get there, no matter how green your destination."