BEIJING, July 21 (Reuters Life!) - The "Bird's Nest" national stadium is the pride of Beijing and one of the iconic structures of China's 2008 Olympic Games, but the men and women who built it may never see it coming to life.
As the opening ceremony of the Games approaches, the army of migrant workers who worked on the city's 31 Olympic projects are packing their bags and heading back to their rural homes as part of a city clean-up campaign that starts in earnest this week.
"Once the work is finished I will leave, I will plant the beds here, then in Tiananmen and then I will go home," said He Jingling, a worker from Henan province who came to Beijing to plant flowers in areas of Beijing that are expected to be filled with tourists and world athletes during the Olympics.
Beijing's pre-Olympic clean-up involves halting construction in the city, shutting factories and limiting the number of cars on the road to help combat chronic pollution, which is one of the biggest headaches for the Games' organisers.
It is also accompanied by a security crackdown.
As the work stops, many of the estimated four million people, who descended on Beijing to toil long hours for a wage slightly better than what they would make at home, are leaving.
Already, migrant workers are queuing at bus and railway stations to go home or to other prosperous cities in the hope of finding work.
There is no official law stating migrants have to leave once the job is complete, but many lack the proper paperwork to stay.
Identity card checks have already been stepped up and a 100,000 strong police force has set up security checks both inside and outside the city, leaving unregistered migrants fearful of the authorities.
Wang Xingyue is one of the luckier ones -- his Olympic construction contract runs out after the Games end, giving him a chance to witness the event.
"I will stay until our work is finished, when the Olympics end I will go," he said.
Qin Weizhang and his wife, from Shandong, were leaving Beijing for Inner Mongolia, where they heard of work opportunities after their Olympic construction contract ended.
He said he would miss the opportunity to see the Olympics in his own country, but work came first.
"We do not have the time. I want to see the Olympics but I have to earn money," he added.
Zhang Zhanxin, an associate professor at China's main government think-tank the Chinese Academy of Social Sciences, said migrant workers are often discriminated against by city-dwellers who look down on them and make them feel unwelcome.
Human rights groups also say migrant workers are vulnerable to exploitation in the workplace and often lack basic health care and protection.
"People in the countryside are relatively poor and so their children only finish primary or middle school. So basically, people from rural areas are less educated and city-dwellers call them uncultured," Zhang said.
"People from the countryside also rarely come to the big cities and because they are unaccustomed to city rules and habits they are looked down on."
Writing by Miral Fahmy, editing by Ben Blanchard