Migrants have always been tempted to the world's biggest cities by tales of fortunes made and streets paved with gold.

Similar stories abound about the Gulf Arab States — Saudi Arabia, Qatar, the United Arab Emirates, Kuwait and Bahrain — whose transformation over the past four decades from desert outposts to modern cities has attracted millions of the world's most impoverished workers.

Dubai, with its artificial islands, megamalls and seven-star hotels, along with Qatar's new World Cup stadiums have only been possible due to years of graft by cheap foreign labor, imported mostly from Asia and Africa.

Read more: Qatar 2022: FIFA admits violation of workers' standards

The promise of much higher wages than at home, however, frequently fails to materialize. Low and unskilled migrants often end up trapped for years in their host countries, indebted, exploited and forced to work long hours in hazardous or brutally hot conditions.

As if they have not suffered enough, hundreds of thousands of migrant workers are now being cast aside following a decade of slower growth in the Gulf following the 2008/09 financial crisis and as Arab countries try to wean themselves off their reliance on foreign labor in the private sector.

Fewer foreigners needed

Saudi Arabia, for example, sent home 1.1 million foreigners over 18 months between early 2017 and late 2018.

Several migrant-sending countries have also reported lower demand for their workers; Pakistan's Economic Survey 2018-19 showed a 40% decline in workforce requirements from Saudi Arabia and a similar fall from the UAE — a country made up of 90% immigrants.

Read more: Qatari laws target pregnant migrant workers

India, too, reported a 9% drop in remittances from its workers abroad in 2016, much of which was attributed to fewer jobs and lower wages in the Gulf states. The Indian state of Kerala, famous for the emigration of many of its workers, has reported a drop in those leaving.

Omar Al-Ubaydli, director of research from the Bahrain Center for Strategic, International and Energy Studies (Derasat) confirmed there was "large-scale worker repatriation" from the Gulf's most populous country.

He described how Saudi Arabia's workforce nationalization program, which encourages unemployed Saudi citizens to train for jobs usually undertaken by foreigners, has moved into full gear.

"[Saudi] citizens now represent a rapidly growing share of retail jobs, especially in sectors such as telecommunications. In supermarkets, cashier positions are overwhelmingly staffed by citizens now," said Al-Ubaydli.

Read more: German human rights institute criticizes exploitation of migrant workers

Saudization to help jobless locals

Saudization, as it's known, was initially trialed in the early 2000s but failed to bring down the jobless rate among young locals.

The program was revived three years ago, dividing private firms into six categories — with individual targets for hiring Saudi citizens. Companies also face much higher levies for recruiting foreign workers.

Al-Ubaydli predicted that job opportunities for migrants were likely to continue to fall because of the new regulatory hurdles as well as a slowing economy.

"This is most likely to be the case for low- and medium-level administrative and technical jobs, as these [positions] are both desirable and feasible to citizens," he told DW.

Meanwhile, a 20-year real estate boom in Dubai — probably the most famous of the UAE's seven emirates — appears to have come to an end, leading to mass layoffs in the construction sector.

The city's respected travel and tourism industries have suffered too, amid a contracting economy.

Read more: Saudi execution spotlights domestic workers' vulnerable lives

More layoffs predicted

Immigration experts have predicted that more low-skilled workers in the hospitality, engineering and construction sectors will face the chop if the region enters recession next year, along with the rest of the world, as many economists predict.

Returning workers could pose a significant problem for sending countries like India and the Philippines, many of whom already struggle with high rates of unemployment and poverty.

The UAE's own Emiratization program has also struggled until recently. While Emiratis make up a high proportion of public sector workers, both highly- and lower-skilled jobs in the private sector are still overwhelmingly done by foreigners.

But with unemployment among Emiratis at 13%, the government has now identified 800,000 jobs that it says could be filled by citizens.

The average Emirati family is wealthier than their Saudi equivalent, so local workers are less likely to take up retail, construction and low-level administration posts, which spells trouble for the lucrative jobs of many higher-skilled foreigners from India, the Middle East and the West.

Despite the recent exodus, Gulf states will continue to rely on vast numbers of foreign workers to help finish their ambitious infrastructure projects. Saudi Arabia, for example, plans to build a $500 billion (€446 billion) smart megacity close to its border with Egypt and Jordan.

Even so, behind the region's ultramodern, shiny image still lies a near-feudal system for employing migrant workers, who are often coaxed into forced labor, according to Human Rights Watch.

Desperate circumstances at home often prompt thousands more migrants to take the plunge and move to the Gulf, despite the many stories about workers being forced to accept much lower wages than agreed and migrants deported while being owed several months of unpaid wages.

Then there's the horrific treatment of domestic and construction workers, thousands of whom return home each year in body bags. Tens of thousands more foreigners remain trapped in Gulf countries every year when their work visas expire, petrified of being caught and with no funds to return home.

Read more: Welfare of Filipino workers focus of talks during Duterte Gulf tour

Some Gulf states have made efforts to better protect foreign workers, reforming their Kafala systems that force migrant workers to have an in-country sponsor with restrictions on changing employers. 

"Countermeasures include inspections [of premises] combined with sanctions, as well as working with the sending countries," said Al-Ubaydli, adding that Bahrain was the first to issue new flexi-visas to all foreigners.

But faced with tighter economic conditions and political pressure to reduce the jobless rate among locals, these countries are likely to keep repatriating tens of thousands of foreigners each year, meaning the Arabian dream of millions of impoverished migrants may turn out to be just a mirage.