The currently nameless city of five million would be home to 660 hospitals, 1,250 mosques and churches, and a theme park four times the size of Disneyland – all to be completed within seven years. Could it happen?

Egypt’s capital has moved two-dozen times in the country’s 5,000-year history, but its current seat of power has remained unchanged since AD 969. That was the year when Fatimid invaders began to build a grand enclosure to house their new mosques and palaces – a private city known to its residents as al-Qahera, and eventually to the world as Cairo.

But a millennium on, and nearly 20 million inhabitants later, Cairo’s time might finally be up – if Egyptian officials are to be believed. The government has announced plans to pass Cairo’s baton to another foreign-helmed development. Just as al-Qahera once was, this new capital is to be built from scratch – in this case by the Emirati businessman behind the Burj Khalifa – on virgin sands to the east of its predecessor.

“Egypt has more wonders than any other country in the world, and provides more works that defy description,” said the bombastic housing minister, Mostafa Madbouly, as he unveiled the £30bn project in front of 30 visiting emirs, kings and presidents, and hundreds of would-be investors. “This is why it is necessary for us as Egyptians to enrich this picture – and to add to it something that our grandchildren will be able to say enhances Egypt’s characteristics.”

The scale of the plans certainly defy historical norms. If completed, the currently nameless city would span 700 sq km (a space almost as big as Singapore), house a park double the size of New York’s Central Park, and a theme park four times as big as Disneyland – all to be completed within five to seven years.

According to the brochure, there will be exactly 21 residential districts, 25 “dedicated districts”, 663 hospitals and clinics, 1,250 mosques and churches, and 1.1m homes housing at least five million residents.

Facebook Twitter Pinterest Traffic in Tahrir Square. Cairo’s population is forecast to double over the next 40 years. Photograph: Reuters

In terms of population, that would make it the biggest purpose-built capital in human history – nearly as large as Islamabad (population: an estimated 1.8 million), Brasilia (2.8 million), and Canberra (380,000) put together.

In certain quarters in Egypt, these astonishing numbers have been hailed by those who desperately hope a new capital can symbolise a process of national renewal under President Abdel Fatah al-Sisi, after several years of deep social division, political upheaval and economic crisis.

Writing in a state-owned newspaper, columnist Sayed el-Bably confidently said the city exemplified how the economic conference at which it was announced would allow Egypt to “convert dreams into facts and projects”. In a nod to failed attempts to build a new capital under Hosni Mubarak, Bably said that Egyptians can now “think, dream, and look forward to the completion of what we previously thought was impossible”.

But the problem for the likes of Bably and Madbouly is that there are also those who doubt this particular dream will ever reach reality.

“Based on historic and global track records, trying to build a new city from scratch is a massive gamble,” says Brent Toderian, Vancouver’s former chief planner, and a consultant for several cities outside of the Middle East. “The most concerning thing to me was the speed at which this is intended to be built – five to seven years. That’s incredibly fast. And if you build it that fast, it will be a ghost town, like most other development plays have been.”

Toderian cites less ambitious projects in China – places like Caofeidian, which hoped to attract a million residents but ended up with only a few thousand. Dubai is an obvious counter-example of success. But elsewhere in the UAE, the new “city” called Masdar (founded, incidentally, by the minister now driving Emirati investment in Egypt, Sultan al-Jaber) was supposed to house 50,000 people by now. Instead, it has just a few hundred.

Facebook Twitter Pinterest A model of the planned new capital was displayed for investors during the Egypt Economic Development Conference in Sharm el-Sheikh. Photograph: Amr Abdallah Dalsh/Reuters

Pressed by the Guardian, Madbouly said he already had the money to build at least 100 sq km of the new capital, including a new parliament. “We are committed for the first phase,” he says. “We have already a very clear plan.”

But in Egypt, even the best urban plans have tended to go awry. Egypt has a history of building unfinished towns in the desert, the product of a decades-old belief that satellite developments will curb overcrowding in its main cities. In theory, the strategy is based in logic: around 96% of Egyptians live on just 4% of Egyptian land, and as the population mushrooms, relocating some of the former might solve the congestion in the latter.

But experience, time and again, has suggested otherwise. These 22 existing “new towns” – some of them more than 30 years old – still collectively hold little more than a million residents, and contain thousands of empty homes. Far from Cairo’s madding crowds, they are in theory an attractive prospect for many Egyptians. But in practice, most cannot afford to move there.

In the most notorious example, New Cairo, a recent suburb to the east of its namesake, was meant to attract several million residents. But after a decade and a half it still only holds a few hundred thousand – an irony lost on Egypt’s investment minister, Ashraf Salman, when he quipped that Cairo’s yet-to-be-named replacement would be “the new New Cairo”.

David Sims, a Cairo-based urban planner, has spent years cataloguing the failures of Egypt’s satellite cities, culminating in last week’s well-timed publication of his latest book – Egypt’s Desert Dreams: Development or Disaster? Sims leans towards the latter.

“It’s just a bunch of crazy figures,” he says. “The scale is huge, and there are questions like: how are you going to do the infrastructure? How are you going to get the water? How will they move all these ministries? In other words, I think it’s just desperation. It will be interesting to see if anything comes of it, but I rather doubt it.”

The reason earlier desert settlements failed to attract residents is largely due to a lack of infrastructure and employment. Places like New Cairo have not provided enough jobs for poorer residents, or affordable transport to areas where they could find more work. “There is a demand to live there, but it’s a demand from a very specific group of people, and it’s not a very big demographic,” says Nick Simcik Arese, an anthropologist at the Oxford Programme for the Future of Cities, and a former resident of, and researcher in, the new desert town of Haram City. “People do want to abandon Cairo and live in their secessionary envelope. But to do that you need a car, and that means you have to have a certain income to live there.”

Facebook Twitter Pinterest The suburb of New Cairo was meant to attract several million residents, but a decade on is only home to a few hundred thousand. Photograph: Sean Smith for the Guardian

Historically, the Egyptian government has forced people to live in areas on Cairo’s periphery, by evicting them from poor inner-city areas, and relocating them to the desert towns. But once there, their lives exemplify why the crowds have not followed in their wake. “Governments think they can just move people to new areas, but actually people go where they want to go,” said Simcik Arese. “For a lot of people, their homes are also their workshops, and that can’t happen out in the desert tower blocks. Their entire business and support system collapses. Their access to clients, materials, and supplies evaporates.”

For Herbert Girardet, the author of a dozen books on urban theory, this isn’t the most urgent concern. He feels Egypt’s new capital stands a good chance of providing better employment opportunities than its predecessors, mainly because Egypt’s vast government will be relocated there. Instead, his biggest worries lie in the city’s carbon footprint. Its architects claim it will uphold “the highest stands of sustainability”. But in the rush to design it, Girardet wonders if the finer details of waste disposal and green power were lost.

“What happens to the waste of this city, where does its energy come from? You have to ask whether these ideas are built into the concept or not,” says Girardet, who sets out a vision for green urban planning in his new book Creative Regenerative Cities. “It’s true that Cairo as a city is massively congested, and there is probably a need for a new capital city. But it seems to me that it would be a city driven above all else by developers keen to create prestige, rather than long-term sustainability.”

Even if he’s wrong, the sustainability of the existing capital would still stay unaddressed. In justifying the desire for a new city, Madbouly said that something had to be done to lighten the load on Cairo, whose projected population will be 40 million by 2050. But Cairo’s plight will ironically worsen if resources and attention are diverted to new projects elsewhere, as one Egyptian commentator argued this weekend.

Writing for Cairobserver, a blog about the current capital, Khaled Fahmy, a history professor at the American University in Cairo, said: “Assuming that the aim of building a new administrative capital is to alleviate the pressure from downtown Cairo where the majority of government offices are located, and assuming, for argument’s sake, that the 5 million inhabitants will actually be moved from overcrowded city, what will happen to the rest of us?”

The fear is that Egypt’s capital, if it gets built, will be just as exclusive and private a city as al-Qahera was when it began back in 969.

Additional reporting: Manu Abdo