An export recovery in the world's most populous country is running up against an unexpected constraint – manpower.

With Chinese exports back to their early 2008 levels, factory owners are worried about their ability to service a surge in orders now that a new manufacturing cycle has begun after the annual lunar new year holidays.

The problem is particularly acute in southern Guangdong province and its Pearl river delta manufacturing heartland near Hong Kong, the region known as “the workshop of the world”.

Guangdong accounts for one-third of China's exports and would rank as one of the world's 10 largest exporters if it were a country in its own right. But the province's ability to attract and retain migrant labour from China's vast interior is slipping.

“Labour availability is tight right now in Guangdong compared to other regions,” said Paul Hussey, chief executive of Strix. The Isle of Man company, which dominates the global market for thermostatic controls on electric kettles, maintains most of its manufacturing operations in the provincial capital, Guangzhou.

Quantifying labour shortages is extremely difficult given large variances by region, industry and skill level. Earlier this week, recruiters for Galanz, the world's largest manufacturer of microwave ovens, were offering production line workers a relatively robust monthly base wage of Rmb1,700 ($250). Skilled technicians in much greater demand were commanding 65 per cent more.

In Dongguan, a manufacturing centre near Guangzhou, the local government estimates there is now just one worker for every two jobs.

Beijing's successful economic stimulus programme has contributed to the coastal scramble for labour, by increasing investment and employment opportunities elsewhere. “Fiscal stimulus has spurred jobs growth in the interior provinces,” Ben Simpfendorfer, Royal Bank of Scotland economist in Hong Kong, said.

In December, China unveiled the world's fastest passenger train service between Guangzhou and the central city of Wuhan, covering 1,100km in just three hours. The Harmony Express line has reduced travel time between Guangzhou and Shaoguan, an industrial backwater in Guangdong's remote mountain region, to just 40 minutes, anchoring local workers closer to home.