A new campaign in Israel is proposing an unusual solution to the country's housing crisis - move Ben-Gurion airport out to sea.

The Natbag 2020 campaign proposes vacating the state-owned site of the airport - known in Hebrew by the acronym Natbag - within eight years, and using it to build a city with 500,000 homes.

The airport would move a mile offshore, connected to the mainland by road and rail. There are already several offshore airports in existence, most famously Japan's Kansai International Airport.

"The airport is a waste of land, such a scarce resource here," said one of the campaign's founders, Yehiel Rosenfeld, head of the structural engineering and construction management programme at the Technion-Israel Institute of Technology.

Another of the founders, Israel Goodovitch, former city engineer for Tel Aviv municipality, said: "You can solve the housing problem very easily - you have the best of all infrastructure [at the airport complex], including electricity, water and a train station. It's the best site in the country."

The Ben Gurion site has electricity, water and rail. It's ideal for a new city

He said that moving the airport would also solve the problem of planes causing noise pollution in central Israel, and increase the airport's security as it would be further from the Green Line.

According to Mr Goodovitch's projections, the value of the land at Ben-Gurion, if sold for housing, would be 500 billion shekels (£85 bn), while the cost of building a new airport out at sea would be, at the most, 20 billion shekels (£3.4 bn). The current airport buildings, he said, could be transformed into shopping malls and other public buildings needed for the new city.

The Natbag 2020 activists originally came together a few months ago to lobby for the relocation of the domestic Dov Hoz Airport (Sde Dov) from north Tel Aviv, where they say it unnecessarily occupies prime real estate with a sea view.

However, in view of the summer's social protests, they decided to expand their scope to Ben Gurion Airport. Their campaign, launched January 1, presents an offshore airport as capable of taking over both Ben Gurion and Dov Hoz's operations.

The Transportation Ministry has not stated a position on the idea of moving either airport or both offshore, and did not respond to a request for a comment.

However, it has announced that it is interested in relocating Dov Hoz Airport, and that it is proposing the establishment of an inter-ministerial committee to look at the possibility of doing so by 2019.