AFP, BEIJING: They fuelled their nation’s dramatic economic rise, toiling in jobs far from home, but China’s migrant workers are now finding themselves increasingly unwelcome as authorities try to cap the population explosions in key cities. Lin Huiqing moved to Beijing to look for work when his children were still in diapers. For the last eighteen years, he has seen his family just once a year, the rest spent doing the hard labour most Beijingers would prefer to avoid.

The 50-year-old is one of hundreds of millions of migrants who moved from the countryside to the cities, a colossal demographic shift that made China’s ascent possible.

But last month Lin was evicted from the village where he lived on the capital’s outskirts, another victim of a city-wide demolition plan to limit Beijing’s population to 23 million by 2020 — a target that could come at the cost of its economy.

“If I go home, I have no way to support my wife and kids,” Lin lamented.

According to the Communist Party mouthpiece People’s Daily, the city plans to demolish 40 million square metres of “illegal” structures.

Many are the homes and shops of low-income migrants like Lin.

When he first arrived in Beijing, Lin and his friends pooled their money and took out loans to purchase delivery trucks.

He made a living hauling the wares of small-scale shopkeepers and traders, but the moving business has taken a hit as the city condemns buildings en masse, evicting tens of thousands into the winter cold.

“Our customers are commoners like us,” he said. “With their small businesses shut down, there’s no stock for us to move. We’re basically unemployed now.”

Authorities say the campaign, which kicked into high gear after a fire in an illegal structure killed 19 in November, is needed to clean the city up once and for all.

But it is also removing vibrant chunks of Beijing’s economy, such as retail and small scale manufacturing, and throwing into chaos other sectors like delivery, the bedrock of the booming e-commerce trade.

Relegated to the periphery, migrants have kept China’s economy humming, handling the difficult, dirty and sometimes dangerous work that the city’s permanent residents won’t do.

Urban industries like construction, domestic work and sanitation are almost completely staffed by migrants.

Eli Friedman, associate professor of international and comparative labor at Cornell University, said China’s biggest cities “simply cannot function without migrant workers”.

“If every non-local were to actually be removed from cities like Beijing, Shanghai, and Guangzhou, these economic engines for the whole country would completely collapse,” he told the news agency.

But that is exactly what is happening, said Li Ning, one of the 60,000 delivery drivers who criss-cross Beijing’s streets.

Li was recently evicted from a village on the city’s outskirts, forcing him into an apartment where the rent quadrupled.

Then authorities came for his delivery company’s warehouse, forcing staff to sort packages on the sidewalk and sending his income plummeting.